Automated document processing system using full image scanning

ABSTRACT

A document processing system comprises an input receptacle for receiving documents. A transport mechanism receives the documents from the input receptacle and transports the documents past a full image scanner and a discrimination unit. An output receptacle receives the documents from the transport mechanism after being transported past the full image scanner and the discrimination unit. The full image scanner includes means for obtaining a full video image of said documents, means for obtaining a image of a selected area of said documents, and means for obtaining information contained in said selected area of said document. The discrimination unit includes means for determining the authenticity of said document. A system controller directs the flows of documents over the transport mechanism.

RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 08/814,978, filedMar. 11, 1997 now U.S. Pat. No. 6,363,164; which is a completeapplication claiming the benefit of U.S. application Ser. No.60/031,604, filed Nov. 27, 1996, and is a continuation-in-part of U.S.application Ser. No. 08/664,262, filed May 13, 1996, now issued as U.S.Pat. No. 5,982,918.

FIELD OF INVENTION

The present invention relates to document processing systems such asautomatic teller machines and currency redemption machines.

SUMMARY OF THE INVENTION

The primary object of the invention is to provide a document andcurrency processing system capable of processing documents utilizingfull image scanning and a currency discriminator.

It is a further object of the invention is to provide a documentprocessing system capable of processing documents utilizing full imagescanning.

It is another object of the invention is to provide a currencyprocessing system capable of processing currency utilizing a currencydiscriminator.

It is another object of the invention to provide a document processingsystem capable of processing all types of documents and interfacing withall types of outside accounting systems.

It is still another object of the invention to provide a documentprocessing system which obtains information by performing full imagescanning of documents and utilizes this information to determineadditional information such as the value of the document;

It is yet another object of the invention to provide a documentprocessing system which is coupled to an outside accounting system suchthat deposits and withdrawals from the outside accounting system areprocessed substantially immediately;

It is yet another object of the invention to provide a system wheredeposits are processed substantially immediately.

It is a further object of the invention to provide a document processingsystem whereby the full image of the scanned document can becommunicated to a central office.

It is yet another object of the invention to provide a currency anddocument processing system which provides all the benefits of anautomated teller machine.

Other aspects and advantages of the present invention will becomeapparent upon reading the following detailed description and inreference to the drawings.

In accordance with the present invention, the foregoing objectives arerealized by providing a document processing system comprising an inputreceptacle for receiving documents; a transport mechanism receiving saiddocuments from said input receptacle and transporting said documentspast a full image scanner and a discrimination unit; an outputreceptacle for receiving said documents from said transport mechanismafter being transported past said full image scanner and discriminationunit; said full image scanner including means for obtaining a full videoimage of said documents, means for obtaining a image of a selected areaof said documents, and means for obtaining information contained in saidselected area of said document, said discrimination unit including meansfor determining the authenticity of said document; and a systemcontroller for directing the flows of documents on said transportmechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a shows a block diagram of the components of a document andcurrency processing system with a single output bin according toprinciples of the present invention;

FIG. 1b is a perspective view of one embodiment of the processing systemwith a video screen and keyboard according to principles of the presentinvention;

FIG. 1c is a diagram of the document processing system with touch screenaccording to principles of the present invention;

FIG. 1d is a block diagram of the document processing system with touchscreen and keyboard according to principles of the present invention,

FIG. 1e is a block diagram of the document processing system with dualoutput bins according to principles of the present invention;

FIG. 1f is a block diagram of the document processing system with aplurality of output bins according to principles of the presentinvention;

FIG. 1g is a block diagram of the document processing system without adiscrimination unit and having a single output receptacle according toprinciples of the present invention;

FIG. 1h is a block diagram of the document processing system without adiscrimination unit and having dual output receptacles according toprinciples of the present invention;

FIG. 1i is a block diagram of the document processing system without adiscrimination unit and having a plurality of output receptaclesaccording to principles of the present invention;

FIG. 1j is a cut-away view of the document processing systems showingthree output bins.

FIG. 1k is a cut-away view of the document processing systems showingfour output bins,

FIG. 1l is a cut-away view of the document processing systems showingsix output bins;

FIG. 1m is a view of a document being scanned by the full image scannerin the wide dimension;

FIG. 1n is a view of a document being scanned by the full image scannerin the narrow dimension;

FIG. 1o is a view of a compact document processing system according toprinciples of the present invention;

FIG. 1p is a block diagram of the document processing system withmodules to insert smart cards, dispense smart cards, and insert opticalmedia according to principles of the present invention;

FIG. 1q illustrates the document processing system according toprinciples of the present invention;

FIG. 1r is a block diagram of the document processing system with coinsorter according to principles of the present invention;

FIG. 1s is a perspective view of a document processor system having twooutput bins;

FIG. 1t is a side view of an evaluation device depicting varioustransport rolls in side elevation according to one embodiment of thepresent invention;

FIGS. 1u-v are a diagrams of networks of full image scanners accordingto principles of the present invention;

FIGS. 1w-y are topological diagrams of networks of full image scannersaccording to principles of the present invention;

FIG. 2 shows a flowchart describing the operation of the documentprocessing system according to principles of the present invention;

FIG. 3 is a block diagram of the full image scanner according toprinciples of the present invention;

FIG. 4a is a block diagram of the discrimination unit according toprinciples of the present invention;

FIGS. 4b-4 d illustrate the scanning process of the discrimination unitaccording to principles of the present invention;

FIG. 4e illustrates one embodiment of size determining sensors;

FIG. 4f illustrates the operation of the scanning process in thediscrimination unit according to principles of the present invention;

FIGS. 5a and 5 b are graphs illustrating the correlation of scanned andmaster patterns according to principles of the present invention;

FIG. 6 illustrates a multiple scanhead according to principles of thepresent invention;

FIG. 7 illustrates another embodiment of the multiple scanheadsaccording to principles of the present invention;

FIG. 8 depicts another embodiment of the scanning system according toprinciples of the present invention;

FIG. 9 depicts another embodiment of the scanning system according toprinciples of the present invention;

FIG. 10 is a top view of a staggered scanhead arrangement according toprinciples of the present invention;

FIGS. 11a and 11 b are flowcharts illustrating the operation of thediscrimination unit according to principles of the present invention;

FIG. 12 shows a block diagram of a counterfeit detector according toprinciples of the present invention;

FIG. 13 is a flow diagram of the discrimination unit according toprinciples of the present invention;

FIG. 14 is a graphical representation of the magnetic data pointsgenerated by two types of currency according to principles of thepresent invention;

FIG. 15 shows a functional block diagram illustrating one embodiment ofthe currency discrimination unit according to principles of the presentinvention;

FIGS. 16a and 16 b show a flowchart illustrating the steps inimplementing the discrimination unit according to principles of thepresent invention;

FIG. 17 illustrate a routine for detecting the overlapping of billsaccording to principles of the present invention;

FIGS. 18a-18 c show one embodiment of the document authenticating systemin the discrimination unit according to principles of the presentinvention;

FIG. 19 shows a functional block diagram illustrating one embodiment ofthe document authenticating system according to principles of thepresent invention;

FIG. 20 shows a modified version of the document authenticating systemaccording to principles of the present invention;

FIG. 21 shows the magnetic characteristics of bills;

FIG. 22 shows other magnetic characteristics of bills;

FIGS. 23 and 24 illustrate bills being transported across sensorsaccording to principles of the present invention;

FIG. 25 is a flowchart illustrating the steps performed in opticallydetermining the denomination of a bill according to principles of thepresent invention;

FIG. 26 is a flowchart illustrating the steps performed in opticallydetermining the denomination of a bill based on the presence of asecurity thread according to principles of the present invention;

FIG. 27 is a flowchart illustrating the steps performed in opticallydetermining the denomination of a bill based on the color of thesecurity thread according to principles of the present invention;

FIG. 28 is a flowchart illustrating the steps performed in opticallydetermining the denomination of a bill based on the location and colorof the security thread according to principles of the present invention;

FIG. 29 is a flowchart illustrating the steps performed in magneticallydetermining the denomination of a bill according to principles of thepresent invention;

FIG. 30 is a flowchart illustrating the steps performed in opticallydenominating a bill and authenticating the bill based on thread locationand/or color information;

FIG. 31 is a flowchart illustrating the steps performed in denominatinga bill based on thread location and/or color information and opticallyauthenticating the bill;

FIG. 32 is a flowchart illustrating the steps performed in opticallydetermining the denomination of a bill and magnetically authenticatingthe bill according to principles of the present invention;

FIG. 33 is a flowchart illustrating the steps performed in magneticallydetermining the denomination of a bill and optically authenticating thebill according to principles of the present invention;

FIG. 34 is a flowchart illustrating the steps in denominating the billaccording to principles of the present invention;

FIG. 35 is a flowchart illustrating the steps performed in denominatingthe bill both optically and magnetically according to principles of thepresent invention;

FIG. 36 is a flowchart illustrating the steps in denominating the billmagnetically and based on thread location according to principles of thepresent invention;

FIG. 37 is a flowchart illustrating the steps performed in denominatinga bill optically, based on thread location and magnetically according toprinciples of the present invention;

FIG. 38 is a flowchart illustrating the steps performed in denominatinga bill based on a first characteristic and authenticating it based on asecond characteristic according to principles of the present invention;

FIGS. 39-47 illustrate alternative methods for denominating and/orauthenticating according to principles of the present invention;

FIGS. 48a-48 c illustrate control panels;

FIGS. 49a, 49 b, 50 a, 50 b, 51 a, 51 b, and 52-53 illustrate alternatemeans for entering the value of no-call documents according toprinciples of the present invention;

FIG. 54 illustrates one embodiment of the control panel according toprinciples of the present invention;

FIG. 55 shows the touch screen according to principles of the presentinvention;

FIG. 56a is a flowchart of conducting a document transaction accordingto principles of the present invention;

FIGS. 56b, 56 c, and 56 d are flowcharts of the funds distributionalgorithm according to principles of the present invention;

FIG. 56e is a flowchart of an alternate funds distribution algorithmaccording to principles of the present invention;

FIG. 56f is a flowchart of the coin sorting algorithm according toprinciples of the present invention;

FIG. 57a illustrates means for entering the value of a no-call documentaccording to principles of the present invention;

FIG. 57b illustrates means for entering the value of a no-call documenton a touch screen according to principles of the present invention;

FIG. 58 is perspective view of a disc-type coin sorter embodying thepresent invention, with a top portion thereof broken away to showinternal structure;

FIG. 59 is an enlarged horizontal section taken generally along line59—59 in FIG. 58;

FIG. 60 is an enlarged section taken generally along line 62—62 in FIG.59, showing the coins in full elevation;

FIG. 61 is an enlarged section taken generally along line 63—63 in FIG.59, showing in full elevation a nickel registered with an ejectionrecess;

FIG. 62 is a diagrammatic cross-section of a coin and an improved coindiscrimination sensor embodying the invention;

FIG. 63 is a schematic circuit diagram of the coin discrimination sensorof FIG. 62;

FIG. 64 is a diagrammatic perspective view of the coils in the coindiscrimination sensor of FIG. 62;

FIG. 65a is a circuit diagram of a detector circuit for use with thediscrimination sensor of this invention;

FIG. 65b is a waveform diagram of the input signals supplied to thecircuit of FIG. 65a;

FIG. 66 is a perspective view of an outboard shunting device embodyingthe present invention;

FIG. 67 is a section taken generally along line 67—67 in FIG. 66;

FIG. 68 is a section taken generally along line 68—68 in FIG. 66,showing a movable partition in a nondiverting position; and

FIG. 69 is the same section illustrated in FIG. 68, showing the movableportion in a diverting position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As illustrated in FIGS. 1a and 1 b, a user deposits bills or documentsinto an input receptacle 16. By “currency”, “documents”, or “bills” itis meant to include not only conventional U.S. or foreign bills, such as$1 bills, but also to include checks, deposit slips, coupon and loanpayment documents, food stamps, cash tickets, savings withdrawaltickets, check deposit slips, savings deposit slips, and all otherdocuments utilized as a proof of deposit at financial institutions. Itis also meant by the term “documents” to include loan applications,credit card applications, student loan applications, accountinginvoices, debit forms, account transfer forms, and all other types offorms with predetermined fields. By “financial institution documents” itis meant to include all of the above documents with the exception ofcurrency. A transport mechanism 18 transports the documents from theinput receptacle 16 past a full image scanner 12, as the documents areilluminated by a light (not shown). The full image scanner 12, describedin greater detail below, scans the full image of the document,recognizes certain fields within the document, and processes informationcontained within these fields in the document. For example, the fullimage scanner 12 may search for the serial number field when processingU.S. currency, determine the serial number once the field is located,and store the serial number for later use by the system. The system mayalso be used to capture any document image for electronic documentdisplay, electronic document storage, electronic document transfer,electronic document recognition (such as denomination recognition orcheck amount recognition) or any other processing function that can beperformed using an electronic image.

Next, the transport mechanism 18 transports the document past adiscrimination and authentication unit 14 which is also described ingreater detail below. The discrimination and authentication unit 14authenticates the document and, in the case of a bill, determines thedenomination of the bill. On other documents, such as checks, the systemmay capture information such as the check amount, account number, banknumber, or check number. The discrimination and authentication unit 14also directs the transport unit 18 to place the document in the outputreceptacle 20 as described below.

A dispensing unit 22 dispenses funds to a user. For example, when theuser is depositing currency in an account, the system has the capabilityto return all or part of a deposit back to the user in the form ofbills, coins, or other media via the dispensing unit 22. The amount ofpayback to the user may be supplemented by funds from other accounts, aswell, as described below. The dispensing unit 22 is capable of acceptinga variety of media including money orders, smart cards, and checks andmay include separate units directed to accepting a particular type ofmedia.

A controller 10 manages the operation of the system. The controller 10directs the flow of documents from the input receptacle 16 through thetransport mechanism 18, past the full image scanner 12 and thediscrimination and authentication unit 14, and into the outputreceptacle 20. The transport mechanism directs the documents through thesystem such that the documents are scanned either along their widedimension as shown in FIG. 1m. Alternatively, the documents are passedthrough the system such that they are scanned along their narrowdimension as shown in FIG. 1n. The controller 10 also directs thedispensing unit 22 to dispense funds to the user and routes informationfrom the full image scanner 12 and the discrimination and authenticationunit 14 to an interface 24 which communicates with an outside accountingsystem or central office. The controller is also capable of directinginformation from the outside office through the interface and to acommunications panel 26. Finally, the controller 10 selectivelyprocesses information from the full image scanner 12 and thediscrimination and authentication unit 14 for use by the system.

By “outside accounting system,” it is meant to include the hardware andsoftware associated with accessing, maintaining, tracking, and updatingsavings accounts, checking accounts, credit card accounts, business andcommercial loans, consumer payments, and all other similar accounts atlocations remotely located from the full image scanners. The termincludes three broad types of systems: systems where deposits are made,systems where withdrawals are made; and systems where both deposits andwithdrawals are made. Although the outside accounting system describedherein is described as being employed at a financial institution such asa bank, it will be understood that any business, public or privateinstitution, or individual can employ an outside accounting system toprocess transactions. By “financial institution” it is meant to includesavings and loans, investment houses, and all other types of financialinstitutions whether private, public, or government. The followingdescription is in terms of banks but it also includes all financialinstitutions as well.

Various types of payments are made between customers of a financialinstitution using a full image scanner and the accounting system at aselected financial institution. First, payments are made from onefinancial institution to another financial institution to settleaccounts. Second, payments are made from a retail customer to a givenfinancial institution or from the financial institution to the givenretail customer. Third, financial institutions can issue payments to andreceive payments from the Federal Reserve Banks within each region.Fourth, consumers can make payments or withdraw payments from financialinstitutions. Fifth, businesses of many kinds can make payments to orwithdraw payments from financial institutions. The outside accountingsystem at the financial institution receives information which has beenprocessed at the full image scanner of the present invention. Theoutside accounting system performs different operations based upon thetype of media used in the transaction and the type of accounts accessed.

When checks are utilized in a transaction, the check is tagged with thecustomer checking account number, the bank number, and the FederalReserve Region. If multiple banks are involved in the payment, eachbank's number is tagged to the payment through an endorsement on theback of the check. Alternatively, the system could tag the checkselectronically. In other words, the customer checking account number,bank number, and Federal Reserve region are electronically tagged to thecheck's image. Tagging also occurs on current electronic payments suchas wire transfers.

The outside accounting system processes information associated withchecking accounts which can be held by individual consumers, businesses,trade associations, trusts, non-profit organizations, or any otherorganization. Documents utilized in the check account function includechecks, check account deposit slips, debit or credit slips which may beissued by the bank against the checking account, new account applicationforms, and forms for customers to reorder check and deposit slips. Thefull image scanner of the present invent processes all of thesedocuments. The documents could be received at a full image scannerlocated at the teller line, a drive-up window, an ATM, or,alternatively, the documents may be received by mail. If received bymail, the bank employee immediately runs the documents through a fullimage scanner without having to forward the documents to a centrallocation for processing. The outside accounting system maintains arecord of all transactions regarding the checking account, balances, andtracks information associated with a particular check.

Savings accounts are another type of account for which the outsideaccounting system processes information. Savings accounts typicallyreceive some rate of interest payment on the balances held. Individualsmay maintain interest bearing savings accounts at a bank. Depending uponthe terms, a savings account could vary in duration for withdrawal fromimmediate demand for withdrawal to as long as five years. When aconsumer agrees to leave the funds for a longer period of time, thisusually provides the account with a higher earning interest rate.Documents used in a savings account transaction include deposit slips,withdrawal slips, new account application slips and debit or creditslips which can be applied against the account by the given bankinginstitution. The full image scanner of the present invention processesall of these documents. Again, the documents could be received at theteller line, drive-up window, ATM, or by mail, and immediately bescanned at point of entry without transporting the document to a centrallocation. This information is sent to an outside accounting system whereit can be stored, monitored, and analyzed. The accounting systemcompiles statistics on customers and their accounts and maintainscurrent balances, interest earnings, available funds, availableadvances, and records all information concerning deposits andwithdrawals.

Credit card accounts are another type of account that are handled by theoutside accounting system. When a credit card is used in a transaction,the bank typically receives a commission. The full image scanner of thepresent invention reads credit cards which are being used for electronicpayment. The outside accounting system maintains a record of thecustomer's credit limit, available credit, current balance, and payment.Preferably, the outside accounting system does not settle the creditcard balance until the end of the month when the customer pays thebalance due on the account.

The debit card is similar to a credit card but is a newer type of media.With the debit card, the customer's account is immediately debited whenthe transaction takes place. The full image processing system of thepresent invention accepts debit cards and performs the same functionsdescribed above with respect to credit cards.

Smart cards are a new evolving method of payment. Banks, phonecompanies, and transit authorities issue smart cards for use bycustomers. The smart cards have a pre-stored value in place which acustomer draws against. Consumers might deposit cash or write a check orsubmit a savings withdrawal document through the full image scanner topurchase a smart card.

Various other types of documents are maintained by a bank. For example,a bank may maintain a trust for an individual such as a retirement trustaccount. An outside accounting system can maintain all types ofinformation regarding these types of accounts such as account balances,interest earnings, and maturity dates.

The outside accounting system also maintains records and managesinformation concerning mortgages, consumer loans, and student loans. Theoutside accounting system maintains records such as the loan balance,last payment, interest rate, and amount paid.

The outside accounting system also distributes funds between the variousaccounts described above. For example, an individual, with checking andsavings accounts at a bank, may also hold a mortgage with the bank. Theoutside accounting system can make monthly withdrawals from the checkingaccount or savings account to pay the monthly mortgage amount due thebank. To accomplish this, the customer may issue a check for payment andsubmit this against a coupon provided to the customer by the bank withthe required monthly mortgage payment. The coupon and the check (orsavings withdrawal and coupon) are run through the full image scanner(at the teller line or automated teller). The information is read by thefull image scanner and transmitted to the outside accounting systemwhich conducts the required transfers.

A customer could use the outside accounting system to electronicallyremove any funds from an account without issuing a check as paymenttowards their mortgage. Alternately, a bank customer could mail thecheck payment and loan coupon to the bank. Upon receipt, the bankemployee immediately runs the check and coupon through the full imagescanner at any bank location—branch, central offices, payment center,etc. The document would not have to be forwarded to a centralized proofdepartment for handling.

In a like manner, businesses can borrow funds from banks for mortgageson commercial property. Again, monthly payments are required, and thecorporation must withdraw funds from their checking account to makethese monthly payments. Again, an outside accounting system could beutilized to make an electronic payment without the use of checks byusing wire transfer or other methods, or the check for payment and thecoupon may be scanned by the full image scanner. Alternatively, a bankcustomer could mail the check payment and loan coupon to the bank. Uponreceipt, the bank employee immediately runs the check and coupon thoughthe scanner at any bank location—branch, central offices, paymentcenter, etc. Thus, the document would not have to be forwarded to acentralized proof department for handling.

Consumer loan transactions, for example, involving auto loans, homeimprovement loans, and educational loans, is another type of transactionprocessed by the outside accounting system. Payments are typically madeusing the monthly repayment schedule by the issuing of the check payableto the bank for the monthly balance. Full image scanning of the checkand loan coupon could be utilized for this transaction. The payment canbe processed as described above. Alternatively, the customer could mailpayment and the bank could process through its full image scanners.

Various types of business loan transactions are also processed by theoutside accounting system including a “bank line of credit” or“revolving loan.” This type of loan is typically one year in maturity. Agiven business draws up to an authorized amount in a given year. Forexample, a business may have a line of credit with a bank for up to $2million, and, on a daily basis, draw on this line of credit. The typicalcollateral provided for this loan would include accounts receivables,inventory, etc. As long as the business has receivables to support theloan, it can draw up to as much as the authorized amount. Then, when thefinancial position of the business improves, the business pays down thisrevolving loan either by issuing a check payable to the bank or throughwire electronic transfer from the business's cash account to the loanpayment. The full image scanner could be used to accept such checkpayments and the outside accounting system at the bank processes thesepayments as described above.

Other types of loans, such as term loans which might have a five-yearmaturity with a scheduled principle repayment and interest paymentrequired on a monthly or quarterly basis, are processed and tracked bythe outside accounting system. Longer term loans, with collateral suchas buildings, are also available that might have a 10 to 15 year life.

Banks sometimes underwrite bonds or other issues of securities bycorporations. For example, a business may hold an industrial revenuebond issued by a city in the amount of $1.5 million. However, in supportof the business's credit, the bank guarantees payment if the businesscould not perform. The business pays a small interest rate (for example,¼ or 1% per year) for the bank's guarantee. Checks are one method usedby banks for such payments. Therefore, the full image scanner andoutside accounting system may be utilized to process this type oftransaction, as described above.

Another important service provided by the outside accounting system forbusiness accounts is cash management. This can be provided by lock boxservices or sweep accounts. For example, a business needs a minimumoperating cash balance in their checking account each day to meetrequirements for payment to vendors or employees, for example. Each day,hundreds of payments from various customers of the business arereceived, typically by check. The checks are deposited into the generalaccount of the business. When the business's account balances exceedsits operating requirements, the outside accounting system at the bankautomatically “sweeps” extra funds from the non-interest bearing accountto an interest bearing account such as commercial paper.

In a similar manner, many companies have customer payments directed to abank “lock box.” This lock box address is at a bank location and allcustomer payments to the company are diverted to this lock box address.This insures that the payments are deposited as quickly as possible sothat the bank's commercial customers have immediate use of the funds atthe bank. The next day the outside accounting system at the bank advisesthe business which payments were received into the account and thebusiness adjusts its accounts receivables balance one day later,creating a timing problem due to the delay.

The full image scanner of the present invention enables a business toscan the documents through the scanner at the business's location (thus,eliminating the need to first send payments to a bank lock box location)and receive immediate credit electronically through the outsideaccounting system located at the bank. The check images and other imageswould immediately be available via the outside accounting system at thebank for settlement purposes. Therefore, lock box services by banks arehandled on a de-centralized basis at bank customer locations.

Another service the outside accounting system provides is payment ofpayroll accounts. The business instructs the accounting system at thebank of the amounts to withdraw from the business's general account onthe day of payroll and credit the employee payroll accounts. The outsideaccounting system can also provide direct deposits to employee accountswithout actually issuing a check. Therefore, the employees haveimmediate use of their funds.

Businesses often maintain cash balances invested in bank commercialpaper. The bank, via the accounting system, pays interest daily on thecash balances. Deposits and withdrawals are typically handled by apre-authorized officer of the company such as the controller. Movementof funds typically require written authorization including a signatureof the company officer. The full image scanner and outside accountingsystem of the present invention are utilized for withdrawals fromcommercial paper to a checking account or for purchase of commercialpaper. This could be initiated by inserting a pre-designed form with anarea to add the amount filed and authorized signature. The full imagescanner captures the amount and seeks a match for the signature.

The system, via the link with a central office computer 15 , processestransactions substantially immediately. That is, deposits are processedin real time rather than waiting for the end of the day. Also, fullimages of all documents can be stored on mass storage devices 17 at thecentral office. The images could also be stored at the unit itself, orat another remote system. The images could also be temporarily storedand forwarded at a later time.

A personal computer 11 also be connected to the system. The personalcomputer can also process data from the scanning modules. Processing ofscanned data can occur at the personal computer 11, within the fullimage scanning module 12 or the discrimination unit 14, or at thecentral office computer 15. The system also is connected to tellerstation 13 (which includes a video display).

Several full image scanners can be interconnected to form a local areanetwork (LAN). The individual image scanners may be located at tellerstations, in bank vaults, or at businesses, for example. In such anetwork, some or all image processing is accomplished at the imagescanner and not at some centralized location. In other words, theprocessing functionality is “distributed” in such an arrangement. Theindividual LANs may have a different physical layouts or topologies.Referring now to FIG. 1w, full image scanners 6054, 6056, 6058, and 6060are connected to common bus 6062. Bus 6062 is coupled to an interface6052. The interface communicates with an outside accounting system whichfunctions as described above. The bus-based network topology isinexpensive, reliable, and requires the least amount of cable for anyLAN topology.

A LAN using a ring topology is illustrated in FIG. 1x. Full imagescanners 6054, 6056, 6058, and 6060 retransmit information to adjacentscanners using point-to-point links. The scanners communicate with othernetworks through an interface 6052. Although more expensive than the bustopology, the ring topology lends itself to being able to transmitinformation over greater distances.

A LAN using a star topology is illustrated in FIG. 1y where a centralfull image scanner 6058 is connected to full image scanners 6054, 6056,6060, and 6062. The central full image scanner communicates to othernetworks through an interface 6052. An advantage to the star topology isenhanced network management. Because all traffic passes the central fullimage scanner 6058, traffic monitoring is simple and detailed networkreports are easy to produce. Enhanced security is inherently a part ofthis type of topology since the central unit can keep tables of useraccess rights as well as acceptable passwords. Also, the network caneasily control who logs onto any remote device present on the network.

Referring now to FIG. 1u, there is illustrated another image processingnetwork according to the present invention. An outside accounting system6036 communicates with front end processor (FEP) 6038. The FEP 6038 is asoftware programmable controller that relieves the outside accountingsystem 6036 of many networking and data communications tasks. The FEPpolls devices, performs error checking and recovery, character codetranslation, and dynamic buffer control. The FEP also serves as a dataconcentrator concentrating several low speed transmissions into asteady, high-speed flow of data. Full image scanners 6040, 6044, and6046 communicate with the FEP 6038 (and the outside accounting system6036) via cluster controller 6042. Cluster controller 6042 serves as aninterface between the outside accounting system 6036 and the scanners6040, 6044, and 6046. The image processing device 6036 has amaster/slave relationship with the scanners 6040, 6044, and 6046 andpolls, via FEP 6038, the devices and determines if they wish tocommunicate.

Another image processing network is described in connection with FIG.1v. In this network, gateways are used to connect networks which havedifferent network architectures. Gateways use all seven layers of theOSI model and perform protocol conversion functions at the Applicationlayer. An outside accounting system 6148 is coupled to FEP 6150 a whichis connected to a token-ring interface coupler (TIC) gateway 6150 b. TICgateway 6150 b provides connections to token ring networks 6156, 6162,and 6164 which include other full image scanners.

The highest performance LAN gateway is the link between a token-ringnetwork 6156 and the image processing device's FEP 6150 a via the TICgateway 6150 b. The TIC 6150 b permits a 4 mbps or 16 mbps connectiondepending upon the hardware used. The TIC 6150 b is viewed by the hostas a cluster controller; the outside accounting system polls the TIC6150 b which in turn polls any units on the token-ring network 6156.

The network also contains a remote LAN gateway which functions as agateway to another token ring LAN 6162. For example, the gateway 6161functions as a cluster controller and communicates with the FEP usingIBM's SDLC protocol via synchronous modems 6154 and 6155 at both sites.The synchronous modems 6154 and 6155 can dial up the FEP at speeds up to64 kbps.

Remote X.25 LANs (which use the X.25 packet switching protocol andcontain full image scanners) can also communicate with the host via X.25gateways. A gateway 6151 with an adapter card functions as a clustercontroller and runs special gateway 6151 software that runs over a givenprotocol and communicates with the X.25 network. A local coaxial gateway6160 is also provided which allows a workstation on the LAN to emulate adistributed function terminal (DFT) mode of processing.

It should be realized that the units connected to particular gatewaysare in no way limited to use with a particular gateway. In fact, thegateways and units can be interchanged and other types of equipment canbe used to structure the network as is known to those skilled in theart.

The communication panel 26 displays information to the user and acceptsuser commands. The panel 26 consists of a video screen 50 onto whichinformation to the user is displayed by the system and a keyboard 52 foraccepting commands from a user. As shown in FIG. 1c, the communicationspanel 26 can consist of a touch screen 27 or as shown in FIG. 1d, acombination of a touch screen 27 and keyboard 29. A slot 54 is used forreceiving a user's identification card. The user inserts the card intothe slot 54 to access the machine. The user deposits documents into bin56. Loose currency is dispensed from slot 58, strapped currency fromreceptacle 60, and loose or rolled coin at receptacle 62.

As shown in FIG. 1p, other modules can be added to the system. A smartcard acceptance module 63 is provided for accepting smart card. A smartcard dispensing module 65 is provided for dispensing smart cards. Anoptical reader module 67 is also provided for accepting and dispensingoptical media.

An audio microphone 64 a and speaker 64 b allow two-way communicationbetween the user and a central office, for example, with a teller at abank's central office. Thus, during the operating hours of a financialinstitution, bank personnel are connected to the system by the audiomicrophone 64 a and speaker 64 b. The central office computer 15 (whichincludes a video terminal) also receives and displays full video imagesof the documents from the system. If the documents are not recognizable,the image is forwarded to the bank employee for observation on theterminal. The bank employee could then discuss the document with thecustomer. In this case, the bank employee could decide to accept thedocument immediately for credit after reviewing the image on theterminal. With a full image scan, enough information may have beenscanned on an unrecognizable document that review by the bank employeeon the terminal will enable the bank employee to accurately call thevalue of the document. Additionally, the image of a document may bepresented on a teller's monitor. By reviewing the data, the teller maybe able to enter missing data via their keyboard, if the image isrecognizable. If the teller is near the machine and an image on themonitor is unclear, the teller may remove the document from the scanner,inspect the document, and enter the missing data. The value could alsobe entered by the denomination keys and other information by aalphanumeric keypad, as described below, or with a mouse andapplications software. Additionally, the value could be entered by atouch screen device or by any combination of the input means describedabove. The document would then be placed in back of the outputreceptacle 20 and processing would continue. In some situations, thecustomer might enter the value or other information concerning theunidentified documents. This entry would be via the keyboard and creditwould be given to the customer's account only after the document isverified by bank personal. In other situations, the customer may merelyhold onto the document.

A mentioned previously, the system has a slot for the insertion of acustomer identification card. Alternatively, the customer might enter aPIN identification number through the keyboard. After identification ofthe customer is determined, then the customer submits a document (suchas a check or savings account withdrawal slip) and immediate payment tothe customer is made.

The output receptacle 20 can be a single bin as shown in FIG. 1a intowhich all documents transported by the transport mechanism 18 arestored. Alternatively, the output receptacle 20 can consist of dual binsas shown in FIG. 1e. In the case of dual bins, identifiable documentsare placed into the first bin and unidentifiable documents are placedinto the second bin. Additionally, as shown in FIG. 1f, any number ofoutput bins can be used to store the documents. For example, currency ofparticular denominations can be stored in separate bins. For example,one bin each can be used to store $1, $5, $10, $20, $50, and $100 bills.

As shown in FIG. 1g, the full image scanner can be used without thediscrimination unit with a single output receptacle. Alternatively, asshown in FIG. 1h, a full image scanner can be used in a system without adiscrimination unit with two output bins or receptacles. Finally, asshown in FIG. 1i, the full image scanner can be used in a system withouta discrimination unit in a system containing any number of output bins.

FIG. 1s depicts an exterior perspective view and FIG. 1t is a side viewof a multi-pocket document processing system 5010 according to oneembodiment of the present invention. According to one embodiment thedocument processing system 5010 is compact having a height (H) of about17½ inches, width (W) of about 13½ inches, and a depth (D) of about 15inches. The evaluation device 5010 may be rested upon a tabletop.

In FIGS. 1s and 1 t, documents are fed, one by one, from a stack ofdocuments placed in an input receptacle 5012 into a transport mechanism.The transport mechanism includes a transport plate or guide plate 240for guiding documents to one of a plurality of output receptacles 5217 aand 5217 b. Before reaching the output receptacles 5217 a, 5217 b adocument can be, for example, evaluated, analyzed, authenticated,discriminated, counted and/or otherwise processed by a full imagescanning module. The results of the above process or processes may beused to determine to which output receptacle 5217 a, 5217 b a documentis directed. In one embodiment, documents such as currency bills aretransported, scanned, and identified at a rate in excess of 800 bills ordocuments per minute. In another embodiment, documents such as currencybills are transported, scanned, and identified at a rate in excess of1000 bills or documents per minute. In the case of currency bills, theidentification includes the determination of the denomination of eachbill.

The input receptacle 5012 for receiving a stack of documents to beprocessed is formed by downwardly sloping and converging walls 205 and206 (see FIG. 1t) formed by a pair of removable covers (not shown) whichsnap onto a frame. The converging wall 206 supports a removable hopper(not shown) that includes vertically disposed side walls (not shown).One embodiment of an input receptacle is described and illustrated inmore detail in U.S. patent application Ser. No. 08/450,505, filed May26, 1995, entitled “Method and Apparatus for Discriminating and CountingDocuments”, now issued as U.S. Pat. No. 5,687,963, which is incorporatedby reference in its entirety. The document processing system 5010 inFIG. 1s has a touch panel display 5015 in one embodiment of the presentinvention which displays appropriate “functional” keys when appropriate.The touch panel display 5015 simplifies the operation of themulti-pocket document processing system 5010. Alternatively oradditionally physical keys or buttons may be employed.

From the input receptacle 5012, the documents are moved in seriatim froma bottom of the stack along a curved guideway 211 (shown in FIG. 1t)which receives documents moving downwardly and rearwardly and changesthe direction of travel to a forward direction. Although shown as beingfed from the bottom, the documents can be fed from the top, front, orback of the stack. The type of feeding used could be friction feed, avacuum feed, or any other method of feeding known to those skilled inthe art. A stripping wheel mounted on a stripping wheel shaft 219 aidsin feeding the documents to the curved guideway 211. The curvature ofthe guideway 211 corresponds substantially to the curved periphery of adrive roll 223 so as to form a narrow passageway for the bills along therear side of the drive roll 233. An exit end of the curved guideway 211directs the documents onto the transport plate 240 which carries thedocuments through an evaluation section and to one of the outputreceptacles 5217 a, 5217 b.

Stacking of the documents in one embodiment is accomplished by a pair ofdriven stacking wheels 5212 a and 5213 a for the first or upper outputreceptacle 5217 a and by a pair of stacking wheels 5212 b and 5213 b forthe second or bottom output receptacle 5217 b. The stacker wheels 5212a,b and 5213 a,b are supported for rotational movement about respectiveshafts 214 a,b journalled on a rigid frame and driven by a motor (notshown). Flexible blades of the stacker wheels 5212 a and 5213 a deliverthe documents onto a forward end of a stacker plate 214 a. Similarly,the flexible blades of the stacker wheels 5212 b and 5213 b deliver thebills onto a forward end of a stacker plate 214 b.

A diverter 260 directs the documents to either the first or secondoutput receptacle 5217 a, 5217 b. When the diverter is in a lowerposition, documents are directed to the first output receptacle 5217 a.When the diverter 260 is in an upper position, documents proceed in thedirection of the second output receptacle 5217 b.

FIGS. 1j-l depict multi-pocket document processing system 10, such as acurrency discriminators, according to embodiments of the presentinvention. FIG. 1j depicts a three-pocket document processing system 10.FIG. 1k depicts a four-pocket document processing system 10. FIG. 11depicts a six-pocket document processing system 10.

The multi-pocket document processing systems 10 in FIGS. 1j-l have atransport mechanism which includes a transport plate or guide plate 240for guiding currency documents to one of a plurality of outputreceptacles 217. The transport plate 240 according to one embodiment issubstantially flat and linear without any protruding features. Beforereaching the output receptacles 217, a document can be, for example,evaluated, analyzed, authenticated, discriminated, counted and/orotherwise processed.

The multi-pocket document processing systems 10 move the documents inseriatim from a bottom of the stack along the curved guideway 211 whichreceives documents moving downwardly and rearwardly and changes thedirection of travel to a forward direction. Although shown as being fedfrom the bottom, the documents can be fed from the top, front, or backof the stack. An exit end of the curved guideway 211 directs thedocuments onto the transport plate 240 which carries the documentsthrough an evaluation section and to one of the output receptacles 217.A plurality of diverters 260 direct the documents to the outputreceptacles 217. When the diverter 260 is in a lower position, documentsare directed to the corresponding output receptacle 217. When thediverter 260 is in an upper position, documents proceed in the directionof the remaining output receptacles.

The multi-pocket document processing systems 10 of FIGS. 1j-l accordingto one embodiment includes passive rolls 260, 251 which are mounted onan underside of the transport plate 240 and are biased intocounter-rotating contact with their corresponding driven upper rolls 223and 241. Other embodiments include a plurality of follower plates whichare substantially free from surface features and are substantiallysmooth like the transport plate 240. The follower plates 262 and 278 arepositioned in spaced relation to transport plate 240 so as to define acurrency pathway therebetween. In one embodiment, follower plates 262and 278 have apertures only where necessary for accommodation of passiverolls 268, 270, 284, and 286.

The follower plate, such as follower plate 262, works in conjunctionwith the upper portion of the transport plate 240 to guide a bill fromthe passive roll 251 to a driven roll 264 and then to a driven roll 266.The passive rolls 268, 270 are biased by H-springs into counter-rotatingcontact with the corresponding driven rolls 264 and 266.

The general operation of the automated document processing system isillustrated in FIG. 2. The user conducts a transaction at step 10 a.During the transaction step 10 a, the user places documents into theinput receptacle 16, the full image scanner 12 scans a full image of thedocuments, selected parts of the image are processed by the imagescanner 12, the discrimination and authentication unit 14 authenticatesthe document, and the document is placed in the output receptacle 20.During the transaction step 10 a, any interaction with personnel at acentral office, for example, with a bank teller, occurs. As previouslydescribed, the system may also include a smart card processing module,modules which accept and read all forms of magnetic and optical media,and modules which dispense smart cards and all forms of optical andmagnetic media.

An alarm condition may be generated during a transaction. At step 10 b,the system determines whether an alarm condition is present. If theanswer is affirmative, then at step 10 c the system responds to thealarm condition. The response may be automatic or may require manualaction by the user. If the response is automatic, the system preferablyflashes a warning light, for example a 24 VAC external light driven by arelay. If the response required is manual, the user is required toperform some manual action and instructions of how to proceed may bedisplayed to the user on a user display screen, as described below.Alarm conditions occur when the user presses a help key; when a currencydispenser becomes empty; when more than a programmable predeterminedamount of foreign currency is detected; upon a system error condition;and when a bin is full. If the answer to step 10 b is negative or uponcompletion of step 10 c, operation continues at step 10 d.

After the alarm condition is tested or handled, the amount deposited inthe transaction is stored at step 10 d for later use. The values arepreferably stored in a computer memory. Next, at step 10 e, the user ormachine distributes the deposited amount stored in step 10 d. Step 10 eis also described in greater detail below and can, for example, consistof receiving the deposited amount in the form of bills, allocating it toa savings account, or receiving part of the deposit back in bills andcrediting the remainder to a bank savings account. At step 10 f, theuser is given the choice of conducting a new transaction. If the answeris affirmative, the system returns to step 10 a which is describedabove. If the user answers in the negative, then the machine stops.

The full image scanner 12 is now described in detail. In accordance withthe present invention, the image scanner may be of the type disclosed inU.S. Pat. No. 4,888,812 which is herein incorporated by reference in itsentirety. As shown in FIG. 3, the front and back surfaces of thedocuments are scanned by scan heads 80 and 82 and the images processedinto video image data by electronic circuitry. The scan heads 80 and 82are preferably charge coupled scanner arrays and generate a sequence ofanalog signals representing light and dark images defining the image onthe document. The scan heads 80 and 82 are arranged for simultaneouslyscanning both the front and back of the documents and are connectedrespectively to analog-to-digital converters 84 and 86 which convert theanalog values into discrete binary gray scale values of, for example,256 gray scale levels. The scan heads are capable of obtaining images ofvarying resolutions. The particular resolution chosen, which can bevaried by the user, is selected based upon the type of document beingscanned, as is known in the art.

The high resolution gray scale image data from the analog-to-digitalconverters 84 and 86 is directed to an image data preprocessor 88 inwhich the data may be enhanced and smoothed and which serves to locatethe edges of successive documents and discard irrelevant data betweendocuments. If the documents are slightly skewed, the image preprocessor88 can also perform rotation on the image data to facilitate subsequentprocessing.

The image data is monitored for unacceptable image quality by imagequality unit 90. For example, the image quality unit 90 and monitors thedistribution of gray scale values in the image data and create ahistogram. As is well known in the art, acceptable quality images have adistribution of gray scale values within certain prescribed limits. Ifthe gray scale distribution of the histogram falls outside these limits,this is indicative of poor image quality and an error condition isgenerated.

The image data is transmitted from the quality unit 90 to the imageprocessor 92. As is known in the art, the optical scanners canadditionally scan specified fields on the faces of the document. Forexample, when processing checks, the scan head may search for the “$”symbol as a coordinate to the left of the numeric check amount fieldbox. As is known in the art, a straight coordinate system or dimensionsystem is used where known dimensions of the box are used to locate thefield. Also, when scanning currency, the system searches for the serialnumbers printed at defined locations which the image processor 92 canlocate. The processor 92 can be programmed to locate fields for varioustypes of currency and perform processing as follows. Based on scanningcertain areas on the currency or document, the processor 92 firstidentifies the type of currency, for example, U.S. bank notes. Then,based on the outcome of the previous step, certain fields of interestare located, and the information stored for use by the system. Theprocessor 92 may also compresses the image data, as is known in the art,in preparation for transmission to an outside location.

The amount of image data per document may vary depending upon the sizeand nature of the document and the efficiency of the data compressionand reduction for that particular document. To insure that no data islost in the event that the volume of image data may temporally exceedthe transfer capacity of the high speed data channel, a prechannelbuffer 94 interposed prior to the data channel, which is connected tothe controller 10. The capacity of the pre-channel buffer 94 iscontinually monitored by the controller 10 so that appropriate actionmay be taken if the buffer becomes overloaded. The compressed videoimage data is received by the controller 10 over a high-speed datachannel 96 and is initially routed to temporary storage. The imagebuffer is preferably of a size capable of storing the image data from atleast several batches or runs of checks or similar documents. Thecontroller 10 in the full image scanner performs the functions ofanalyzing the data. Alternatively, as discussed above, analysis of thedata can occur at the central office computer 15 or at a personalcomputer 11 attached to the system.

The personal computer or alternate means may be used to create images ofdocuments that are electronic images only, without scanning documents.For example, the EDGE system by Cummins-Allison corporation could beused. In such a system, computer software electronically creates animage of a document such as a check. A special printer (not shown) isconnected to the system to print documents with special fields such asmagnetic ink fields.

A plurality of document processing systems may be connected in a “huband spokes” network architecture as is known in the art. In order toprevent congestion, the image buffer on each document processing systemstores data until polled by the central office computer or outsideaccounting system. When polled, the data is uploaded to the centraloffice computer or accounting system.

Other scanning modules and methods can be used in place or in additionto the particular one described above. These include CCD array systems,multi-cell arrays and other well-known scanning techniques. Examples ofthese techniques and devices are described in U.S. Pat. No. 5,023, 782;U.S. Pat. No. 5,237,158; U.S. Pat. No. 5,187,750; and U.S. Pat. No.4,205,780 all of which are incorporated by reference in their entirety.The scanning module can also be a color image scanner such as the typedescribed in U.S. Pat. No. 5,335,292 which is incorporated by referencein its entirety.

The discrimination and authentication unit may contain a single ormultiple head scanner. Before explaining such a multiple head scanner,the operation of a scanner having a single scanhead is first described.In particular, a currency discrimination system adapted to U.S. currencyis described in connection with FIGS. 4a-4 d. Subsequently,modifications to such a discrimination and authentication unit will bedescribed in obtaining a currency discrimination and authentication unitin accordance with the present invention. Furthermore, while theembodiments of the discrimination and authentication unit describedbelow entail the scanning of currency bills, the discrimination andauthentication unit of the present invention is applicable to otherdocuments as well. For example, the system of the present invention maybe employed in conjunction with stock certificates, checks, bonds, andpostage and food stamps, and all other financial institution documents.

Referring now to FIG. 4a, there is shown a functional block diagramillustrating a currency discriminating unit having a single scanhead.The unit 910 includes a bill accepting station 912 where stacks ofcurrency bills that need to be identified and counted are positioned bythe transport mechanism. Accepted bills are acted upon by a billseparating station 914 which functions to pick out or separate one billat a time for being sequentially relayed by a bill transport mechanism916, according to a precisely predetermined transport path, acrossscanhead 918 where the currency denomination of the bill is scanned andidentified. Scanhead 918 is an optical scanhead that scans forcharacteristic information from a scanned bill 917 which is used toidentify the denomination of the bill. The scanned bill 917 is thentransported to a bill stacking station 920 where bills so processed arestacked for subsequent removal.

The optical scanhead 918 of FIG. 4a comprises at least one light source922 directing a beam of coherent light downwardly onto the billtransport path so as to illuminate a substantially rectangular lightstrip 924 upon a currency bill 917 positioned on the transport pathbelow the scanhead 918. Light reflected off the illuminated strip 924 issensed by a photodetector 926 positioned directly above the strip. Theanalog output of photodetector 926 is converted into a digital signal bymeans of an analog-to-digital (ADC) converter unit 928 whose output isfed as a digital input to a central processing unit (CPU) 930.

While scanhead 918 of FIG. 4a is an optical scanhead, it should beunderstood that it may be designed to detect a variety of characteristicinformation from currency bills. Additionally, the scanhead may employ avariety of detection means such as magnetic, optical, electricalconductivity, and capacitive sensors. Use of such sensors is discussedin more detail below, for example, in connection with FIG. 15.

Referring again to FIG. 4a, the bill transport path is defined in such away that the transport mechanism 916 moves currency bills with thenarrow dimension of the bills being parallel to the transport path andthe scan direction. Alternatively, the system 910 may be designed toscan bills along their long dimension or along a skewed dimension. As abill 917 moves on the transport path on the scanhead 918, the coherentlight strip 924 effectively scans the bill across the narrow dimensionof the bill. As depicted, the transport path is so arranged that acurrency bill 917 is scanned by scanhead 918 approximately about thecentral section of the bill along its narrow dimension, as shown in FIG.4a. The scanhead 918 functions to detect light reflected from the billas it moves across the illuminated light strip 924 and to provide ananalog representation of the variation in light so reflected which, inturn, represents the variation in the dark and light content of theprinted pattern or indicia on the surface of the bill. This variation inlight reflected from the narrow dimension scanning of the bills servesas a measure for distinguishing, with a high degree of confidence, amonga plurality of currency denominations which the discrimination unit ofthis invention is programmed to handle.

A series of such detected reflectance signals are obtained across thenarrow dimension of the bill, or across a selected segment thereof, andthe resulting analog signals are digitized under control of the CPU 930to yield a fixed number of digital reflectance data samples. The datasamples are then subjected to a digitizing process which includes anormalizing routine for processing the sampled data for improvedcorrelation and for smoothing out variations due to contrastfluctuations in the printed pattern existing on the bill surface. Thenormalized reflectance data so digitized represents a characteristicpattern that is fairly unique for a given bill denomination and providessufficient distinguishing features among characteristic patterns fordifferent currency denominations. This process is more fully explainedin U.S. patent application Ser. No. 07/885,648, filed on May 19, 1992,now issued as U.S. Pat. No. 5,295,196 for a “Method and Apparatus forCurrency Discrimination and Counting,” which is incorporated herein byreference in its entirety.

In order to ensure strict correspondence between reflectance samplesobtained by narrow dimension scanning of successive bills, theinitiation of the reflectance sampling process is preferably controlledthrough the CPU 930 by means of an optical encoder 932 which is linkedto the bill transport mechanism 916 and precisely tracks the physicalmovement of the bill 917 across the scanhead 918. More specifically, theoptical encoder 932 is linked to the rotary motion of the drive motorwhich generates the movement imparted to the bill as it is relayed alongthe transport path. In addition, the mechanics of the feed mechanism(not shown, see U.S. Pat. No. 5,295,196 referred to above) ensure thatpositive contact is maintained between the bill and the transport path,particularly when the bill is being scanned by scanhead 918. Under theseconditions, the optical encoder 932 is capable of precisely tracking themovement of the bill 917 relative to the light strip 924 generated bythe scanhead 918 by monitoring the rotary motion of the drive motor.

The output of photodetector 926 is monitored by the CPU 930 to initiallydetect the presence of the bill underneath the scanhead 918 and,subsequently, to detect the starting point of the printed pattern on thebill, as represented by the thin borderline 917A which typicallyencloses the printed indicia on currency bills. Once the borderline 917Ahas been detected, the optical encoder 932 is used to control the timingand number of reflectance samples that are obtained from the output ofthe photodetector 926 as the bill 917 moves across the scanhead 918 andis scanned along its narrow dimension.

The use of the optical encoder 932 for controlling the sampling processrelative to the physical movement of a bill 917 across the scanhead 918is also advantageous in that the encoder 932 can be used to provide apredetermined delay following detection of the borderline prior toinitiation of samples. The encoder delay can be adjusted in such a waythat the bill 917 is scanned only across those segments along its narrowdimension which contain the most distinguishable printed indiciarelative to the different currency denominations.

In the case of U.S. currency, for instance, it has been determined thatthe central, approximately two-inch (approximately 5 cm) portion ofcurrency bills, as scanned across the central section of the narrowdimension of the bill, provides sufficient data for distinguishing amongthe various U.S. currency denominations on the basis of the correlationtechnique disclosed in U.S. Pat. No. 5,295,196 referred to above.Accordingly, the optical encoder can be used to control the scanningprocess so that reflectance samples are taken for a set period of timeand only after a certain period of time has elapsed since the borderline917A has been detected, thereby restricting the scanning to the desiredcentral portion of the narrow dimension of the bill.

FIGS. 4b-4 d illustrate the scanning process of scanhead 920 in moredetail. Referring to FIG. 4b, as a bill 917 is advanced in a directionparallel to the narrow edges of the bill, scanning via a wide slit inthe scanhead 918 is effected along a segment S of the central portion ofthe bill 917. This segment S begins a fixed distance D inboard of theborderline 917A. As the bill 917 traverses the scanhead 918, a strip sof the segment S is always illuminated, and the photodetector 926produces a continuous output signal which is proportional to theintensity of the light reflected from the illuminated strip s at anygiven instant. This output is sampled at intervals controlled by theencoder, so that the sampling intervals are precisely synchronized withthe movement of the bill across the scanhead 918.

As illustrated in FIGS. 4b and 4 d, it is preferred that the samplingintervals be selected so that the strips s that are illuminated forsuccessive samples overlap one another. The odd-numbered andeven-numbered sample strips have been separated in FIGS. 4b and 4 d tomore clearly illustrate this overlap. For example, the first and secondstrips s1 and s2 overlap each other, the second and third strips s2 ands3 overlap each other, and so on. Each adjacent pair of strips overlapeach other. For U.S. currency, this is accomplished by sampling stripsthat are 0.050 inch (0.127 cm) wide at 0.029 inch (0.074 cm) intervals,along a segment S that is 1.83 inch (4.65 cm) long (64 samples).

The optical sensing and correlation technique is based upon using theabove process to generate a series of stored intensity signal patternsusing genuine bills for each denomination of currency that is to bedetected. According to one embodiment, two or four sets of masterintensity signal samples are generated and stored within system memory,preferably in the form of an EPROM 934 (see FIG. 4a), for eachdetectable currency denomination. The sets of master intensity signalsamples for each bill are generated from optical scans, performed on thegreen surface of the bill and taken along both the “forward” and“reverse” directions relative to the pattern printed on the bill.Alternatively, the optical scanning may be performed on the black sideof U.S. currency bills or on either surface of bills from othercountries. Additionally, the optical scanning may be performed on bothsides of a bill, for example, by placing a scanhead on each side of thebill transport path as described in more detail in U.S. patentapplication Ser. No. 08/207,592 filed Mar. 8, 1994, for a “Method andApparatus for Currency Discrimination.” now issued as U.S. Pat. No.5,467,406, and incorporated herein by reference.

In adapting this technique to U.S. currency, for example, sets of storedintensity signal samples are generated and stored for seven differentdenominations of U.S. currency, i.e., $1, $2, $5, $10, $20, $50 and$100. For bills which produce significant pattern changes when shiftedslightly to the left or right, such as the $2 and the $10 bill in U.S.currency, it is preferred to store two patterns for each of the“forward” and “reverse” directions, each pair of patterns for the samedirection represent two scan areas that are slightly displaced from eachother along the long dimension of the bill. Accordingly, a set of anumber of different master characteristic patterns is stored within thesystem memory for subsequent correlation purposes. Once the masterpatterns have been stored, the pattern generated by scanning a billunder test is compared by the CPU 930 with each of the master patternsof stored intensity signal samples to generate, for each comparison, acorrelation number representing the extent of correlation, i.e.,similarity between corresponding ones of the plurality of data samples,for the sets of data being compared. In the case of checks, the systemcompares the image signature to a stored master signature or to anaccount number.

The CPU 930 is programmed to identify the denomination of the scannedbill as corresponding to the set of stored intensity signal samples forwhich the correlation number resulting from pattern comparison is foundto be the highest. In order to preclude the possibility ofmischaracterizing the denomination of a scanned bill, as well as toreduce the possibility of spurious notes being identified as belongingto a valid denomination, a bi-level threshold of correlation is used asthe basis for making a “positive” call. Such a method is disclosed inU.S. Pat. No. 5,295,196 referred to above. If a “positive” call can notbe made for a scanned bill, an error signal is generated.

Using the above sensing and correlation approach, the CPU 930 isprogrammed to count the number of bills belonging to a particularcurrency denomination as part of a given set of bills that have beenscanned for a given scan batch, and to determine the aggregate total ofthe currency amount represented by the bills scanned during a scanbatch. The CPU 930 is also linked to an output unit 936 (FIG. 4a) whichis adapted to provide a display of the number of bills counted, thebreakdown of the bills in terms of currency denomination, and theaggregate total of the currency value represented by counted bills. Theoutput unit 936 can also be adapted to provide a print-out of thedisplayed information in a desired format.

A procedure for scanning bills and generating characteristic patterns isdescribed in U.S. Pat. No. 5,295,196 referred to above and incorporatedby reference in its entirety and co-pending U.S. patent application Ser.No. 08/243,807, filed on May 16, 1994 and entitled “Method and Apparatusfor Currency Discrimination”, now issued as U.S. Pat. No. 5,633,949.

The optical sensing and correlation technique described in U.S. Pat. No.5,295,196 permits identification of pre-programmed currencydenominations with a high degree of accuracy and is based upon arelatively short processing time for digitizing sampled reflectancevalues and comparing them to the master characteristic patterns. Theapproach is used to scan currency bills, normalize the scanned data andgenerate master patterns in such a way that bill scans during operationhave a direct correspondence between compared sample points in portionsof the bills which possess the most distinguishable printed indicia. Arelatively low number of reflectance samples is required in order to beable to adequately distinguish among several currency denominations.

Now that a single scanhead currency scanner has been described inconnection with scanning U.S. currency, a currency discrimination unitaccording to an embodiment of the present invention will be described.In particular, a discrimination unit that can accommodate bills, checks,or any financial institution document of non-uniform size and/or colorwill be described.

First of all, because currencies come in a variety of sizes, sensors areadded to determine the size of a bill to be scanned. These sensors areplaced upstream of the scanheads to be described below. One embodimentof size determining sensors is illustrated in FIG. 4e. Twoleading/trailing edge sensors 962 detect the leading and trailing edgesof a bill 964 as it passing along the transport path. These sensors inconjunction with the encoder 932 (FIG. 4a) may be used to determine thedimension of the bill along a direction parallel to the scan directionwhich in FIG. 4e is the narrow dimension (or width) of the bill 964.Additionally, two side edge sensors 966 are used to detect the dimensionof a bill 964 transverse to the scan direction which in FIG. 4e is thewide dimension (or length) of the bill 964. While the sensors 962 and966 of FIG. 4e are optical sensors, any means of determining the size ofa bill may be employed.

Once the size of a bill is determined, the potential identity of thebill is limited to those bills having the same size. Accordingly, thearea to be scanned can be tailored to the area or areas best suited foridentifying the denomination and country of origin of a bill having themeasured dimensions.

Secondly, while the printed indicia on U.S. currency is enclosed withina thin borderline, the sensing of which may serve as a trigger to beginscanning using a wider slit, most currencies of other currency systemssuch as those from other countries do not have such a borderline. Thusthe system described above may be modified to begin scanning relative tothe edge of a bill for currencies lacking such a borderline. Referringto FIG. 4f, two leading edge detectors 968 are shown. The detection ofthe leading edge 69 of a bill 970 by leading edge sensors 968 triggersscanning in an area a given distance away from the leading edge of thebill 970, e.g., D₁ or D₂, which may vary depending upon the preliminaryindication of the identity of a bill based on the dimensions of a bill.Alternatively, the leading edge 69 of a bill may be detected by one ormore of the scanheads (to be described below). Alternatively, thebeginning of scanning may be triggered by positional informationprovided by the encoder 932 of FIG. 4a, for example, in conjunction withthe signals provided by sensors 962 of FIG. 4e, thus eliminating theneed for leading edge sensors 968.

However, when the initiation of scanning is triggered by the detectionof the leading edge of a bill, the chance that a scanned pattern will beoffset relative to a corresponding master pattern increases. Offsets canresult from the existence of manufacturing tolerances which permit thelocation of printed indicia of a document to vary relative to the edgesof the document. For example, the printed indicia on U.S. bills may varyrelative to the leading edge of a bill by as much as 50 mils which is0.05 inches (1.27 mm). Thus when scanning is triggered relative to theedge of a bill (rather than the detection of a certain part of theprinted indicia itself, such as the printed borderline of U.S. bills), ascanned pattern can be offset from a corresponding master pattern by oneor more samples. Such offsets can lead to erroneous rejections ofgenuine bills due to poor correlation between scanned and masterpatterns. To compensate, overall scanned patterns and master patternscan be shifted relative to each other as illustrated in FIGS. 5a and 5b. More particularly, FIG. 5a illustrates a scanned pattern which isoffset from a corresponding master pattern. FIG. 5b illustrates the samepatterns after the scanned pattern is shifted relative to the masterpattern, thereby increasing the correlation between the two patterns.Alternatively, instead of shifting either scanned patterns or masterpatterns, master patterns may be stored in memory corresponding todifferent offset amounts.

Thirdly, while it has been determined that the scanning of the centralarea on the green side of a U.S. bill (see segment S of FIG. 4c)provides sufficiently distinct patterns to enable discrimination amongthe plurality of U.S. denominations, the central area may not besuitable for bills originating in other countries. For example, forbills originating from Country 1, it may be determined that segment S₁(FIG. 4f) provides a more preferable area to be scanned, while segmentS₂ (FIG. 4f) is more preferable for bills originating from Country 2.Alternatively, in order to sufficiently discriminate among a given setof bills, it may be necessary to scan bills which are potentially fromsuch set along more than one segment, e.g., scanning a single bill alongboth S₁ and S₂.

To accommodate scanning in areas other than the central portion of abill, multiple scanheads may be positioned next to each other. Oneembodiment of such a multiple scanhead system is depicted in FIG. 6.Multiple scanheads 972 a-c and 972 d-f are positioned next to each otheralong a direction lateral to the direction of bill movement. Such asystem permits a bill 74 to be scanned along different segments.Multiple scanheads 972 a-f are arranged on each side of the transportpath, thus permitting both sides of a bill 74 to be scanned.

Two-sided scanning may be used to permit bills to be fed into a currencydiscrimination unit according to the present invention with either sideface up. An example of a two-sided scanhead arrangement is disclosed inU.S. patent application Ser. No. 08/207,592 filed on Mar. 8, 1994 andissued as U.S. Pat. No. 5,467,406 and incorporated herein by reference.Master patterns generated by scanning genuine bills may be stored forsegments on one or both sides. In the case where master patterns arestored from the scanning of only one side of a genuine bill, thepatterns retrieved by scanning both sides of a bill under test may becompared to a master set of single-sided master patterns. In such acase, a pattern retrieved from one side of a bill under test shouldmatch one of the stored master patterns, while a pattern retrieved fromthe other side of the bill under test should not match one of the masterpatterns. Alternatively, master patterns may be stored for both sides ofgenuine bills. In such a two-sided system, a pattern retrieved byscanning one side of a bill under test should match with one of themaster patterns of one side (Match 1) and a pattern retrieved fromscanning the opposite side of a bill under test should match the masterpattern associated with the opposite side of a genuine bill identifiedby Match 1.

Alternatively, in situations where the face orientation of a bill (i.e.,whether a bill is “face up” or “face down”) may be determined prior toor during characteristic pattern scanning, the number of comparisons maybe reduced by limiting comparisons to patterns corresponding to the sameside of a bill. That is, for example, when it is known that a bill is“face up”, scanned patterns associated with scanheads above thetransport path need only be compared to master patterns generated byscanning the “face” of genuine bills. By “face” of a bill it is meant aside which is designated as the front surface of the bill. For example,the front or “face” of a U.S. bill may be designated as the “black”surface while the back of a U.S. bill may be designated as the “green”surface. The face orientation may be determinable in some situations bysensing the color of the surfaces of a bill. An alternative method ofdetermining the face orientation of U.S. bills by detecting theborderline on each side of a bill is disclosed in U.S. Pat. No.5,467,406. The implementation of color sensing is discussed in moredetailed below.

According to the embodiment of FIG. 6, the bill transport mechanismoperates in such a fashion that the central area C of a bill 74 istransported between central scanheads 972 b and 972 e. Scanheads 972 aand 972 c and likewise scanheads 972 d and 972 f are displaced the samedistance from central scanheads 972 b and 972 e, respectively. Bysymmetrically arranging the scanheads about the central region of abill, a bill may be scanned in either direction, e.g., top edge first(forward direction) or bottom edge first (reverse direction). Asdescribed above with respect to FIG. 4a, master patterns are stored fromthe scanning of genuine bills in both the forward and reversedirections. While a symmetrical arrangement is preferred, it is notessential provided appropriate master patterns are stored for anon-symmetrical system.

While FIG. 6 illustrates a system having three scanheads per side, anynumber of scanheads per side may be utilized. Likewise, it is notnecessary that there be a scanhead positioned over the central region ofa bill. For example, FIG. 7 illustrates another embodiment of thepresent invention capable of scanning the segments S₁ and S₂ of FIG. 4f.Scanheads 976 a, 976 d, 976 e, and 976 h scan a bill 78 along segment SIwhile scanheads 976 b, 976 c, 976 f, and 976 g scan segment S₂.

FIG. 8 depicts another embodiment of a scanning system according to thepresent invention having laterally moveable scanheads 980 a-b. Similarscanheads may be positioned on the opposite side of the transport path.Moveable scanheads 980 a-b may provide more flexibility that may bedesirable in certain scanning situations. Upon the determination of thedimensions of a bill as described in connection with FIG. 4e, apreliminary determination of the identity of a bill may be made. Basedon this preliminary determination, the moveable scanheads 980 a-b may bepositioned over the area of the bill which is most appropriate forretrieving discrimination information. For example, if based on the sizeof a scanned bill, it is preliminarily determined that the bill is aJapanese 5000 Yen bill-type, and if it has been determined that asuitable characteristic pattern for a 5000 Yen bill-type is obtained byscanning a segment 2.0 cm to the left of center of the bill fed in theforward direction, scanheads 980 a and 980 b may be appropriatelypositioned for scanning such a segment, e.g., scanhead 980 a positioned2.0 cm left of center and scanhead 980 b positioned 2.0 cm right ofcenter. Such positioning permits proper discrimination regardless of thewhether the scanned bill is being fed in the forward or reversedirection. Likewise scanheads on the opposite side of the transport path(not shown) could be appropriately positioned. Alternatively, a singlemoveable scanhead may be used on one or both sides of the transportpath. In such a system, size and color information (to be described inmore detail below) may be used to properly position a single laterallymoveable scanhead, especially where the orientation of a bill may bedetermined before scanning.

FIG. 8, depicts a unit in which the transport mechanism is designed todeliver a bill 982 to be scanned centered within the area in whichscanheads 980 a-b are located. Accordingly, scanheads 980 a-b aredesigned to move relative to the center of the transport path withscanhead 980 a being moveable within the range R₁ and scanhead 980 bbeing moveable within range R₂.

FIG. 9 depicts another embodiment of a scanning system according to thepresent invention wherein bills to be scanned are transported in a leftjustified manner along the transport path, that is wherein the left edgeL of a bill 984 is positioned in the same lateral location relative tothe transport path. Based on the dimensions of the bill, the position ofthe center of the bill may be determined and the scanheads 986 a-b mayin turn be positioned accordingly. As depicted in FIG. 9, scanhead 986 ahas a range of motion R₃ and scanhead 986 b has a range of motion R₄.The ranges of motion of scanheads 986 a-b may be influenced by the rangeof dimensions of bills which the discrimination unit is designed toaccommodate. Similar scanheads may be positioned on the opposite side ofthe transport path.

Alternatively, the transport mechanism may be designed such that scannedbills are not necessarily centered or justified along the lateraldimension of the transport path. Rather the design of the transportmechanism may permit the position of bills to vary left and right withinthe lateral dimension of the transport path. In such a case, the edgesensors 966 of FIG. 4e may be used to locate the edges and center of abill, and thus provide positional information in a moveable scanheadsystem and selection criteria in a stationary scanhead system.

In addition to the stationary scanhead and moveable scanhead systemsdescribed above, a hybrid system having both stationary and moveablescanheads may be used. Likewise, it should be noted that the laterallydisplaced scanheads described above need not lie along the same lateralaxis. That is, the scanheads may be, for example, staggered upstream anddownstream from each other. FIG. 10 is a top view of a staggeredscanhead arrangement according to one embodiment of the presentinvention. As illustrated in FIG. 10, a bill 130 is transported in acentered manner along the transport path 132 so that the center 134 ofthe bill 130 is aligned with the center 136 of the transport path 132.Scanheads 140 a-h are arranged in a staggered manner so as to permitscanning of the entire width of the transport path 132. The areasilluminated by each scanhead are illustrated by strips 142 a, 142 b, 142e, and 142 f for scanheads 140 a, 140 b, 140 e, and 140 f, respectively.Based on size determination sensors, scanheads 140 a and 140 h mayeither not be activated or their output ignored.

In general, if prior to scanning a document, preliminary informationabout a document can be obtained, such as its size or color,appropriately positioned stationary scanheads may be activated orlaterally moveable scanheads may be appropriately positioned providedthe preliminary information provides some indication as to the potentialidentity of the document. Alternatively, especially in systems havingscanheads positioned over a significant portion of the transport path,many or all of the scanheads of a system may be activated to scan adocument. Then subsequently, after some preliminary determination as toa document's identity has been made, only the output or derivationsthereof of appropriately located scanheads may be used to generatescanned patterns. Derivations of output signals include, for example,data samples stored in memory generated by sampling output signals.Under such an alternative embodiment, information enabling a preliminarydetermination as to a document's identity may be obtained by analyzinginformation either from sensors separate from the scanheads or from oneor more of the scanheads themselves. An advantage of such preliminarydeterminations is that the number of scanned patterns which have to begenerated or compared to a set of master patterns is reduced. Likewisethe number of master patterns to which scanned patterns must be comparedmay also be reduced.

While the scanheads 140 a-h of FIG. 10 are arranged in a non-overlappingmanner, they may alternatively be arranged in an overlapping manner. Byproviding additional lateral positions, an overlapping scanheadarrangement may provide greater selectivity in the segments to bescanned. This increase in scanable segments may be beneficial incompensating for currency manufacturing tolerances which result inpositional variances of the printed indicia on bills relative to theiredges. Additionally, in one embodiment, scanheads positioned above thetransport path are positioned upstream relative to their correspondingscanheads positioned below the transport path.

In addition to size and scanned characteristic patterns, color may alsobe used to discriminate bills. For example, while all U.S. bills areprinted in the same colors, e.g. a green side and a black side, billsfrom other countries often vary in color with the denomination of thebill. For example, a German 50 deutsche mark bill-type is brown in colorwhile a German 100 deutsche mark bill-type is blue in color.Alternatively, color detection may be used to determine the faceorientation of a bill, such as where the color of each side of a billvaries. For example, color detection may be used to determine the faceorientation of U.S. bills by detecting whether or not the “green” sideof a U.S. bill is facing upwards. Separate color sensors may be addedupstream of the scanheads described above. According to such anembodiment, color information may be used in addition to sizeinformation to preliminarily identify a bill. Likewise, colorinformation may be used to determine the face orientation of a billwhich determination may be used to select upper or lower scanheads forscanning a bill accordingly or compare scanned patterns retrieved fromupper scanheads with a set of master patterns generated by scanning acorresponding face while the scanned patterns retrieved from the lowerscanheads are compared with a set of master patterns generated byscanning an opposing face. Alternatively, color sensing may beincorporated into the scanheads described above. Such color sensing maybe achieved by, for example, incorporating color filters, colored lightsources, and/or dichroic beamsplitters into the currency discriminationunit of the present invention. Various color information acquisitiontechniques are described in U.S. Pat. Nos. 4,841,358; 4,658,289;4,716,456, 4,825,246; and 4,992,860.

The operation of the currency discrimination unit according to oneembodiment of the present invention may be further understood byreferring to the flowchart of FIGS. 11a and 11 b. In the processbeginning at step 100, a bill is fed along a transport path (step 102)past sensors which measure the length and width of the bill (step 104).These size determining sensors may be, for example, those illustrated inFIG. 4e. Next at step 106, it is determined whether the measureddimensions of the bill match the dimensions of at least one bill storedin memory, such as EPROM 960 of FIG. 4e. If no match is found, anappropriate error is generated at step 108. If a match is found, thecolor of the bill is scanned for at step 110. At step 112 it isdetermined whether the color of the bill matches a color associated witha genuine bill having the dimensions measured at step 104. An error isgenerated at step 114 if no such match is found. However, if a match isfound, a preliminary set of potentially matching bills is generated atstep 116. Often, only one possible identity will exist for a bill havinga given color and dimensions. However, the preliminary set of step 116is not limited to the identification of a single bill-type, that is, aspecific denomination of a specific currency system; but rather, thepreliminary set may comprise a number of potential bill-types. Forexample, all U.S. bills have the same size and color. Therefore, thepreliminary set generated by scanning a U.S. $5 bill would include U.S.bills of all denominations.

Based on the preliminary set (step 116), selected scanheads in astationary scanhead system may be activated (step 118). For example, ifthe preliminary identification indicates that a bill being scanned hasthe color and dimensions of a German 100 deutsche mark, the scanheadsover regions associated with the scanning of an appropriate segment fora German 100 deutsche mark may be activated. Then upon detection of theleading edge of the bill by sensors 968 of FIG. 4f, the appropriatesegment may be scanned. Alternatively, all scanheads may be active withonly the scanning information from selected scanheads being processed.Alternatively, based on the preliminary identification of a bill (step116), moveable scanheads may be appropriately positioned (step 118).

Subsequently, the bill is scanned for a characteristic pattern (step120). At step 122, the scanned patterns produced by the scanheads arecompared with the stored master patterns associated with genuine billsas dictated by the preliminary set. By only making comparisons withmaster patterns of bills within the preliminary set, processing time maybe reduced. Thus for example, if the preliminary set indicated that thescanned bill could only possibly be a German 100 deutsche mark, thenonly the master pattern or patterns associated with a German 100deutsche mark need be compared to the scanned patterns. If no match isfound, an appropriate error is generated (step 124). If a scannedpattern does match an appropriate master pattern, the identity of thebill is accordingly indicated (step 126) and the process is ended (step128).

While some of the embodiments discussed above entailed a unit capable ofidentifying a plurality of bill-types, the system may be adapted toidentify a bill under test as either belonging to a specific bill-typeor not. For example, the unit may be adapted to store master informationassociated with only a single bill-type such as a United Kingdom 5 £bill. Such a system would identify bills under test which were UnitedKingdom 5 £ bills and would reject all other bill-types.

The scanheads of the present invention may be incorporated into the unitand used to identify a variety of documents including currency andfinancial institution documents such as checks, deposit slips, couponsand food stamps. For example, the unit may be designed to accommodate anumber of currencies from different countries. Such a unit may bedesigned to permit operation in a number of modes. For example, the unitmay be designed to permit an operator to select one or more of aplurality of bill-types which the system is designed to accommodate.Such a selection may be used to limit the number of master patterns withwhich scanned patterns are to be compared. Likewise, the operator may bepermitted to select the manner in which bills will be fed, such as allbills face up, all bills top edge first, random face orientation, and/orrandom top edge orientation. Additionally, the unit may be designed topermit output information to be displayed in a variety of formats to avariety of peripherals, such as a monitor, LCD display, or printer. Forexample, the unit may be designed to count the number of each specificbill-types identified and to tabulate the total amount of currencycounted for each of a plurality of currency systems. For example, astack of bills could be placed in the bill accepting station 912 of FIG.4a, and the output unit 936 of FIG. 4a may indicate that a total of 370British pounds and 650 German marks were counted. Alternatively, theoutput from scanning the same batch of bills may provide more detailedinformation about the specific denominations counted, for example one100 £ bill, five 50 £ bills, and one 20 £ bill and thirteen 50 deutschemark bills.

FIG. 12 shows a block diagram of a counterfeit detector 210. Amicroprocessor 212 controls the overall operation of the counterfeitdetector 210. It should be noted that the detailed construction of amechanism to convey documents through the counterfeit detector 210 isnot related to the practice of the present invention. Manyconfigurations are well-known in the prior art. An exemplaryconfiguration includes an arrangement of pulleys and rubber belts drivenby a single motor. An encoder 214 may be used to provide input to themicroprocessor 212 based on the position of a drive shaft 216, whichoperates the bill-conveying mechanism. The input from the encoder 214allows the microprocessor to calculate the position of a document as ittravels and to determine the timing of the operations of the counterfeitdetector 210.

A stack of documents (not shown) may be deposited in a hopper 218 whichholds the documents securely and allows the documents in the stack to beconveyed one at a time through the counterfeit detector 210. After thedocuments are conveyed to the interior of the counterfeit detector 210,a portion of the document is optically scanned by an optical sensor 220of the type commonly known in the art. The optical sensor generatessignals that correspond to the amount of light reflected by a smallportion of the document. Signals from the optical sensor 220 are sent toan amplifier circuit 222, which, in turn, sends an output to ananalog-to-digital converter 224. The output of the ADC is read by themicroprocessor 212. The microprocessor 212 stores each element of datafrom the optical sensor 220 in a range of memory locations in a randomaccess memory (“RAM”) 226, forming a set of image data that correspondsto the object scanned.

As the document continues its travel through the counterfeit detector210, it is passed adjacent to a magnetic sensor 228, which detects thepresence of magnetic ink. The magnetic sensor 228 desirably makes aplurality of measurements along a path parallel to one edge of thedocument being examined. For example, the path sensed by the magneticsensor 228 may be parallel to the shorter edges of the document andsubstantially through the document's center. The output signal from themagnetic sensor 228 is amplified by an amplifier circuit 230 anddigitized by the ADC 224. The digital value of each data point measuredby the magnetic sensor 228 is read by the microprocessor 212, whereuponit is stored in a range of memory in the RAM 226. The magnetic sensor228 is capable of reading and identifying all types of magnetic ink. Forinstance, the sensor 228 can read “low dispersion” magnetic inks onchecks. “Low dispersion” magnetic ink is magnetic ink mixed with colorink and used to print the background of checks as well as the name andaddress information on the check.

The digitized magnetic data may be mathematically manipulated tosimplify its use. For example, the value of all data points may besummed to yield a checksum, which may be used for subsequent comparisonto expected values computed from samples of genuine documents. As willbe apparent, calculation of a checksum for later comparison eliminatesthe need to account for the orientation of the document with respect tothe magnetic sensor 228. This is true because the checksum representsthe concentration of magnetic ink across the entire path scanned by themagnetic sensor 228, regardless of variations caused by higherconcentrations in certain regions of the document.

The image data stored in the RAM 226 is compared by the microprocessor212 to standard image data stored in a read only memory (“ROM”) 232. Thestored image data corresponds to optical data generated from genuinedocuments such as currency of a plurality of denominations. The ROMimage data may represent various orientations of genuine currency toaccount for the possibility of a document in the stack being in areversed orientation compared to other documents in the stack. If theimage data generated by the document being evaluated does not fallwithin an acceptable limit of any of the images stored in ROM, thedocument is determined to be of an unknown denomination. The machinestops to allow removal of the document from the stack of currency.

If the image data from the document being evaluated corresponds to oneof the images stored in the ROM 232, the microprocessor 212 compares thechecksum of the magnetic data to one of a plurality of expected checksumvalues stored in the ROM 232. An expected checksum value is stored foreach denomination that is being counted. The value of each expectedchecksum is determined, for example, by averaging the magnetic data froma number of genuine samples of each denomination of interest. If thevalue of the measured checksum is within a predetermined range of theexpected checksum, the document is considered to be genuine. If thechecksum is not within the acceptable range, the operator is signaledthat the document is suspect and the operation of the counterfeitdetector 210 is stopped to allow its retrieval.

If the document passes both the optical evaluation and the magneticevaluation, it exits the counterfeit detector 210 to a stacker 234.Furthermore, the counterfeit detector 210 may desirably include thecapability to maintain a running total of genuine documents, forexample, currency of each denomination.

It should be noted that the magnetic checksum is only compared to theexpected checksum for a single denomination (i.e. the denomination thatthe optical data comparison has indicated). For instance, the only wayin which a bill can be classified as genuine is if its magnetic checksumis within an acceptable range for its specific denomination. For acounterfeit bill to be considered genuine by the counterfeit detector ofthe present invention, it would have to be within an acceptable range inthe denomination-discriminating optical comparison and have adistribution of magnetic ink within an acceptable range for its specificdenomination.

To summarize the operation of the unit, a stack of documents, forexample, bills or checks, is fed by the transport mechanism (element 18in FIG. 1a) into the hopper 218. Each document is transported adjacentto the optical sensor 220, which generates image data corresponding toone side of the document. The document is also scanned by a magneticsensor 228 and a plurality of data points corresponding to the presenceof magnetic ink are recorded by the microprocessor 212. A checksum isgenerated by adding the total of all magnetic data points. The imagedata generated by the optical sensor 220 is compared to stored images,for example, images that correspond to a plurality of denominations ofcurrency. When predetermined information such as the denomination of thebill being evaluated has been determined, the checksum is compared to astored checksum corresponding to a genuine bill of that denomination.The microprocessor 212 generates a signal indicating that the documentis genuine or counterfeit depending on whether said data is within apredetermined range of the expected value. Documents exit thecounterfeit detector 210 and are accumulated in the stacker 234.

FIG. 13 is a flow diagram of an exemplary discrimination unit accordingto an embodiment of the present invention. At step 236, the presence ofa bill approaching the optical sensor 220 is detected by themicroprocessor 212, which initiates an optical scanning operation 238.Image data generated by the optical scanning operation are stored in RAM226. The number of optical samples taken is not critical to theoperation of the present invention, but the probability of accurateclassification of the denomination of a bill increases as the number ofsamples increases.

At step 240, the microprocessor 212 initiates the magnetic scanningoperation. The data points obtained by the magnetic scanning operationmay be stored in the RAM 226 and added together later to yield achecksum, as shown in step 244. Alternatively, the checksum may becalculated by keeping a running total of the magnetic data values byadding each newly acquired value to the previous total. As with theoptical scanning operation, the number of data points measured is notessential, but the chances of accurately identifying a counterfeit billbased on the concentration of magnetic ink improve as the number ofsamples increases. At step 242, the microprocessor determines thedenomination of the bill by comparing the image data to a plurality ofknown images, each of which corresponds to a specific denomination ofcurrency. The bill is identified as belonging to the denominationcorresponding to one of the known scan patterns if the correlationbetween the two is within an acceptable range. At step 246, the checksumresulting from the summation of the magnetic data points is compared toan expected value for a genuine bill of the denomination identified bythe comparison of the image data to the stored data.

The expected value may be determined in a variety of ways. One method isto empirically measure the concentration of magnetic ink on a sample ofgenuine bills and average the measured concentrations. Another method isto program the microprocessor to periodically update the expected valuebased on magnetic data measurements of bills evaluated by thecounterfeit detector over a period of time.

If the checksum of the bill being evaluated is within a predeterminedrange of the expected value, the bill is considered to be genuine.Otherwise, the bill is considered to be counterfeit. As will beapparent, the choice of an acceptable variation from the expectedchecksum determines the sensitivity of the counterfeit detector. If therange chosen is too narrow, the possibility that a genuine bill will beclassified as counterfeit is increased. On the other hand, thepossibility that a counterfeit bill will be classified as genuineincreases if the acceptable range is too broad.

FIG. 14 is a graphical representation of the magnetic data pointsgenerated by both a genuine pre-1996 series one hundred dollar bill(solid line) and a counterfeit one hundred dollar bill (broken line). Aspreviously noted, bills are desirably scanned along a path that isparallel to one of their short edges. The graph shown in FIG. 14 showsmagnetic data obtained by scanning a path passing approximately throughthe center of the bill. The measurements in the region designated “a”correspond to the area at the top of the bill. The area designated “b”corresponds to the central region of the bill and the region designated“c” corresponds to the bottom of the bill. The magnetic measurements forthe genuine bill are relatively high in region a because of the highconcentration of magnetic ink near the top of the bill. Theconcentration of magnetic ink in region b is relatively small and theconcentration in region c is generally between the concentrations inregions a and c.

It should be noted that the concentration of magnetic ink in a typicalcounterfeit bill is uniformly low. Thus, the sum of the all data pointsfor a counterfeit bill is generally significantly lower than for agenuine bill. Nonetheless, as counterfeiting techniques become moresophisticated, the correlation between genuine bills and counterfeitshas improved.

The unit described above increases the chances of identifying acounterfeit bill because the denomination of a bill being evaluated isdetermined prior to the evaluation of the bill for genuineness. Thechecksum of the bill being evaluated is only compared to the expectedchecksum for a bill of that denomination. The process of identifying thedenomination of the bill prior to evaluating it for genuinenessminimizes the chance that a “good” counterfeit will generate a checksumindicative of a genuine bill of any denomination.

Referring next to FIG. 15, there is shown a functional block diagramillustrating one embodiment of a discrimination and authentication unitsimilar to that depicted in FIG. 4a but illustrating the presence of asecond detector. The discrimination and authentication unit 250 includesa bill accepting station 252 where stacks of currency bills that need tobe identified, authenticated, and counted are positioned. Accepted billsare acted upon by a bill separating station 254 which functions to pickout or separate one bill at a time for being sequentially relayed by abill transport mechanism 256, according to a precisely predeterminedtransport path, across two scanheads 260 and 262 where the currencydenomination of the bill is identified and the genuineness of the billis authenticated. In the embodiment depicted, the scanhead 260 is anoptical scanhead that scans for a first type of characteristicinformation from a scanned bill 257 which is used to identify the bill'sdenomination. The second scanhead 262 scans for a second type ofcharacteristic information from the scanned bill 257. While in theillustrated embodiment scanheads 260 and 262 are separate and distinct,it is understood that these may be incorporated into a single scanhead.For example, where the first characteristic sensed is intensity ofreflected light and the second characteristic sensed is color, a singleoptical scanhead having a plurality of detectors, one or more withoutfilters and one or more with colored filters, may be employed (U.S. Pat.No. 4,992,860 incorporated herein by reference). The scanned bill isthen transported to a bill stacking station 264 where bills so processedare stacked for subsequent removal.

The optical scanhead 260 of the embodiment depicted in FIG. 15 comprisesat least one light source 266 directing a beam of coherent lightdownwardly onto the bill transport path so as to illuminate asubstantially rectangular light strip 258 upon a currency bill 257positioned on the transport path below the scanhead 260. Light reflectedoff the illuminated strip 258 is sensed by a photodetector 268positioned directly above the strip. The analog output of thephotodetector 268 is converted into a digital signal by means of ananalog-to-digital (ADC) converter unit 270 whose output is fed as adigital input to a central processing unit (CPU) 272.

The second scanhead 262 comprises at least one detector 274 for sensinga second type of characteristic information from a bill. The analogoutput of the detector 274 is converted into a digital signal by meansof a second analog to digital converter 276 whose output is also fed asa digital input to the central processing unit (CPU) 272.

While scanhead 260 in the embodiment of FIG. 15 is an optical scanhead,it should be understood that the first and second scanheads 260 and 262may be designed to detect a variety of characteristic information fromcurrency bills. Additionally these scanheads may employ a variety ofdetection means such as magnetic or optical sensors. For example, avariety of currency characteristics can be measured using magneticsensing. These include detection of patterns of changes in magnetic flux(U.S. Pat. No. 3,280,974), patterns of vertical grid lines in theportrait area of bills (U.S. Pat. No. 3,870,629), the presence of asecurity thread (U.S. Pat. No. 5,151,607), total amount of magnetizablematerial of a bill (U.S. Pat. No. 4,617,458), patterns from sensing thestrength of magnetic fields along a bill (U.S. Pat. No. 4,593,184), andother patterns and counts from scanning different portions of the billsuch as the area in which the denomination is written out (U.S. Pat. No.4,356,473).

With regard to optical sensing, a variety of currency characteristicscan be measured such as detection of density (U.S. Pat. No. 4,381,447),color (U.S. Pat. Nos. 4,490,846; 3,496,370; 3,480,785), length andthickness (U.S. Pat. No. 4,255,651), the presence of a security thread(U.S. Pat. No. 5,151,607) and holes (U.S. Pat. No. 4,381,447), and otherpatterns of reflectance and transmission (U.S. Pat. No. 3,496,370;3,679,314; 3,870,629; 4,179,685). Color detection techniques may employcolor filters, colored lamps, and/or dichroic beamsplitters (U.S. Pat.Nos. 4,841,358; 4,658,289; 4,716,456; 4,825,246, 4,992,860 and EP325,364). An optical sensing system using ultraviolet light is describedin the assignee's co-pending U.S. patent application Ser. No.08/317,349, filed Oct. 4, 1994, now issued as U.S. Pat. No. 5,640,463,and incorporated herein by reference, and described below.

In addition to magnetic and optical sensing, other techniques ofdetecting characteristic information of currency include electricalconductivity sensing, capacitive sensing (U.S. Pat. No. 5,122,754[watermark, security thread]; U.S. Pat. No. 3,764,899 [thickness]; U.S.Pat. No. 3,815,021 [dielectric properties]; U.S. Pat. No. 5,151,607[security thread]), and mechanical sensing (U.S. Pat. No. 4,381,447[limpness]; U.S. Pat. No. 4,255,651 [thickness]).

Referring again to FIG. 15, the bill transport path is defined in such away that the transport mechanism 256 moves currency bills with thenarrow dimension of the bills parallel to the transport path and thescan direction. Alternatively, the system 250 may be designed to scanbills along their long dimension or along a skewed dimension. As a bill257 moves on the transport path on the scanhead 260, the coherent lightstrip 258 effectively scans the bill across the narrow dimension of thebill. In the embodiment depicted, the transport path is so arranged thata currency bill 257 is scanned by scanhead 260 approximately about thecentral section of the bill along its narrow dimension, as best shown inFIG. 15. The scanhead 260 functions to detect light reflected from thebill as it moves across the illuminated light strip 258 and to providean analog representation of the variation in light so reflected which,in turn, represents the variation in the dark and light content of theprinted pattern or indicia on the surface of the bill. This variation inlight reflected from the narrow dimension scanning of the bills servesas a measure for distinguishing, with a high degree of confidence, amonga plurality of currency denominations which the discrimination andauthentication unit of this invention is programmed to handle.

A series of such detected reflectance signals are obtained across thenarrow dimension of the bill, or across a selected segment thereof, andthe resulting analog signals are digitized under control of the CPU 272to yield a fixed number of digital reflectance data samples. The datasamples are then subjected to a digitizing process which includes anormalizing routine for processing the sampled data for improvedcorrelation and for smoothing out variations due to “contrast”fluctuations in the printed pattern existing on the bill surface. Thenormalized reflectance data so digitized represents a characteristicpattern that is fairly unique for a given bill denomination and providessufficient distinguishing features between characteristic patterns fordifferent currency denominations. This process is more fully explainedin U.S. patent application Ser. No. 07/885,648, filed on May 19, 1992,now issued as U.S. Pat. No. 5,295,196 for “Method and Apparatus forCurrency Discrimination and Counting,” which is incorporated herein byreference in its entirety.

In order to ensure strict correspondence between reflectance samplesobtained by narrow dimension scanning of successive bills, theinitiation of the reflectance sampling process is preferably controlledthrough the CPU 272 by means of an optical encoder 278 which is linkedto the bill transport mechanism 256 and precisely tracks the physicalmovement of the bill 257 across the scanheads 260 and 262. Morespecifically, the optical encoder 278 is linked to the rotary motion ofthe drive motor which generates the movement imparted to the bill as itis relayed along the transport path. In addition, the mechanics of thefeed mechanism (not shown, see U.S. Pat. No. 5,295,196 referred toabove) ensure that positive contact is maintained between the bill andthe transport path, particularly when the bill is being scanned byscanheads 260 and 262. Under these conditions, the optical encoder 278is capable of precisely tracking the movement of the bill 257 relativeto the light strip 258 generated by the scanhead 260 by monitoring therotary motion of the drive motor.

The output of photodetector 268 is monitored by the CPU 272 to initiallydetect the presence of the bill underneath the scanhead 260 and,subsequently, to detect the starting point of the printed pattern on thebill, as represented by the thin borderline 257 a which typicallyencloses the printed indicia on currency bills. Once the borderline 257a has been detected, the optical encoder 278 is used to control thetiming and number of reflectance samples that are obtained from theoutput of the photodetector 268 as the bill 257 moves across thescanhead 260 and is scanned along its narrow dimension.

The detection of the borderline 257 a serves as an absolute referencepoint for initiation of sampling. If the edge of a bill were to be usedas a reference point, relative displacement of sampling points can occurbecause of the random manner in which the distance from the edge to theborderline 257 a varies from bill to bill due to the relatively largerange of tolerances permitted during printing and cutting of currencybills. As a result, it becomes difficult to establish directcorrespondence between sample points in successive bill scans and thediscrimination efficiency is adversely affected. Embodiments triggeringoff the edge of the bill are discussed above, for example, in connectionwith FIGS. 5a and 5 b.

The use of the optical encoder 278 for controlling the sampling processrelative to the physical movement of a bill 257 across the scanhead 260is also advantageous in that the encoder 278 can be used to provide apredetermined delay following detection of the borderline prior toinitiation of samples. The encoder delay can be adjusted in such a waythat the bill 257 is scanned only across those segments along its narrowdimension which contain the most distinguishable printed indiciarelative to the different currency denominations.

The optical sensing and correlation technique are similar to thatdescribed in connection with FIG. 4a and the description made inconnection with FIG. 4a is applicable to FIG. 15.

As a result of the first comparison described above based on thereflected light intensity information retrieved by scanhead 260, the CPU272 will have either determined the denomination of the scanned bill 257or determined that the first scanned signal samples fail to sufficientlycorrelate with any of the sets of stored intensity signal samples inwhich case an error is generated. Provided that an error has not beengenerated as a result of this first comparison based on reflected lightintensity characteristics, a second comparison is performed. This secondcomparison is performed based on a second type of characteristicinformation, such as alternate reflected light properties, similarreflected light properties at alternate locations of a bill, lighttransmissivity properties, various magnetic properties of a bill, thepresence of a security thread embedded within a bill, the color of abill, the thickness or other dimension of a bill, etc. The second typeof characteristic information is retrieved from a scanned bill by thesecond scanhead 262. The scanning and processing by scanhead 262 may becontrolled in a manner similar to that described above with regard toscanhead 260.

In addition to the sets of stored first characteristic information, inthis example stored intensity signal samples, the EPROM 280 stores setsof stored second characteristic information for genuine bills of thedifferent denominations which the system 250 is capable of handling.Based on the denomination indicated by the first comparison, the CPU 272retrieves the set or sets of stored second characteristic data for agenuine bill of the denomination so indicated and compares the retrievedinformation with the scanned second characteristic information. Ifsufficient correlation exists between the retrieved information and thescanned information, the CPU 272 verifies the genuineness of the scannedbill 257. Otherwise, the CPU generates an error. While the embodimentillustrated in FIG. 15 depicts a single CPU 272 for making comparisonsof first and second characteristic information and a single EPROM 280for storing first and second characteristic information, it isunderstood that two or more CPUs and/or EPROMs could be used, includingone CPU for making first characteristic information comparisons and asecond CPU for making second characteristic information comparisons.

Using the above sensing and correlation approach, the CPU 272 isprogrammed to count the number of bills belonging to a particularcurrency denomination whose genuineness has been verified as part of agiven set of bills that have been scanned for a given scan batch, and todetermine the aggregate total of the currency amount represented by thebills scanned during a scan batch. The CPU 272 is also linked to anoutput unit 282 which is adapted to provide a display of the number ofgenuine bills counted, the breakdown of the bills in terms of currencydenomination, and the aggregate total of the currency value representedby counted bills. The output unit 282 can also be adapted to provide aprint-out of the displayed information in a desired format.

The interrelation between the use of the first and second type ofcharacteristic information can be seen by considering FIGS. 16a and 16 bwhich comprise a flowchart illustrating the sequence of operationsinvolved in implementing a discrimination and authentication unitaccording to one embodiment of the present invention. Upon theinitiation of the sequence of operations (step 288), reflected lightintensity information is retrieved from a bill being scanned (step 290).Similarly, second characteristic information is also retrieved from thebill being scanned (step 292). Denomination error and secondcharacteristic error flags are cleared (steps 293 and 294).

Next the scanned intensity information is compared to each set of storedintensity information corresponding to genuine bills of alldenominations the system is programmed to accommodate (step 298). Foreach denomination, a correlation number is calculated. The system then,based on the correlation numbers calculated, determines either thedenomination of the scanned bill or generates a denomination error bysetting the denomination error flag (steps 300 and 302). In the casewhere the denomination error flag is set (step 302), the process isended (step 312). Alternatively, if based on this first comparison, thesystem is able to determine the denomination of the scanned bill, thesystem proceeds to compare the scanned second characteristic informationwith the stored second characteristic information corresponding to thedenomination determined by the first comparison (step 304).

For example, if as a result of the first comparison the scanned bill isdetermined to be a $20 bill, the scanned second characteristicinformation is compared to the stored second characteristic informationcorresponding to a genuine $20 bill. In this manner, the system need notmake comparisons with stored second characteristic information for theother denominations the system is programmed to accommodate. If based onthis second comparison (step 304) it is determined that the scannedsecond characteristic information 10 does not sufficiently match that ofthe stored second characteristic information (step 306), then a secondcharacteristic error is generated by setting the second characteristicerror flag (step 308) and the process is ended (step 312). If the secondcomparison results in a sufficient match between the scanned and storedsecond characteristic information (step 306), then the denomination ofthe scanned bill is indicated (step 310) and the process is ended (step312).

TABLE 1 Sensitivity Denomination 1 2 3 4 5  $1 200 250 300 375 450  $2100 125 150 225 300  $5 200 250 300 350 400 $10 100 125 150 200 250 $20120 150 180 270 360 $50 200 250 300 375 450 $100  100 125 150 250 350

An example of an interrelationship between authentication based on afirst and second characteristic can be seen by considering Table 1.Table 1 depicts relative total magnetic content thresholds for variousdenominations of genuine bills. Columns 1-5 represent varying degrees ofsensitivity selectable by a user of a device employing the presentinvention. The values in Table 1 are set based on the scanning ofgenuine bills of varying denominations for total magnetic content andsetting required thresholds based on the degree of sensitivity selected.The information in Table 1 is based on the total magnetic content of agenuine $1 being 1000. The following discussion is based on asensitivity setting of 4. In this example it is assumed that magneticcontent represents the second characteristic tested. If the comparisonof first characteristic information, such as reflected light intensity,from a scanned billed and stored information corresponding to genuinebills results in an indication that the scanned bill is a $10denomination, then the total magnetic content of the scanned bill iscompared to the total magnetic content threshold of a genuine $10 bill,i.e., 200. If the magnetic content of the scanned bill is less than 200,the bill is rejected. Otherwise it is accepted as a $10 bill.

According to another feature of the present invention, the doubling oroverlapping of bills in the transport system is detected by theprovision of a pair of optical sensors which are co-linearly disposedopposite to each other within the scan head area along a line that isperpendicular to the direction of bill flow, i.e., parallel to the edgeof test bills along their wide dimensions as the bills are transportedacross the optical scan head. The pair of optical sensors S1 and S2 (notshown) are co-linearly disposed within the scan head area in closeparallelism with the wide dimension edges of incoming test bills. Ineffect, the optical sensors S1 and S2 (having corresponding lightsources and photodetectors—not shown) are disposed opposite each otheralong a line within the scan head area which is perpendicular to thedirection of bill flow. These sensors S1 and S2 serve as seconddetectors for detecting second characteristic information, namelydensity.

Although not illustrated in the drawings, it should be noted thatcorresponding photodetectors (not shown) are provided within thescanhead area in immediate opposition to the corresponding light sourcesand underneath the flat section of the transport path. These detectorsdetect the beam of coherent light directed downwardly onto the billtransport path from the light sources corresponding to the sensors S1and S2 and generate an analog output which corresponds to the sensedlight. Each such output is converted into a digital signal by aconventional ADC converter unit (not shown) whose output is fed as adigital input to and processed by the system CPU (not shown), in amanner similar to that indicated in the arrangement of FIG. 15.

The presence of a bill which passes under the sensors S1 and S2 causes achange in the intensity of the detected light, and the correspondingchange in the analog output of the detectors serves as a convenientmeans for density-based measurements for detecting the presence of“doubles” (two or more overlaid or overlapped bills) during the currencyrecognition and counting process. For instance, the sensors may be usedto collect a predefined number of density measurements on a test bill,and the average density value for a bill may be compared topredetermined density thresholds (based, for instance, on standardizeddensity readings for master bills) to determine the presence of overlaidbills or doubles. The above sensors and doubles detection technique isdescribed in more detail in U.S. Pat. No. 5,295,196 which isincorporated herein by reference.

A routine for using the outputs of the two sensors S1 and S2 to detectany doubling or overlapping of bills is illustrated in FIG. 17. Thisroutine uses a determination of the denomination of a bill based onfirst characteristic information to streamline doubles detection whereinsecond characteristic information corresponds to the density of scannedbills. This routine starts when the denomination of a scanned bill hasbeen determined via comparing first characteristic information at step401, as described previously. To permit variations in the sensitivity ofthe density measurement, a “density setting choice” is retrieved frommemory at step 402. The operator makes this choice manually, accordingto whether the bills being scanned are new bills, requiring a higherdegree of sensitivity, or used bills, requiring a lower level ofsensitivity. After the “density setting choice” has been retrieved, thesystem then proceeds through a series of steps which establish a densitycomparison value according to the denomination of the bill. Thus, step403 determines whether the bill has been identified as a $20-bill, andif the answer is affirmative, the $20-bill density comparison value isretrieved from memory at step 404. A negative answer at step 443advances the system to step 405 to determine whether the bill has beenidentified as a $100-bill, and if the answer is affirmative, the$100-bill density comparison value is retrieved from memory at step 406.A negative answer at step 405 advances the system to step 407 where ageneral density comparison value, for all remaining bill denominations,is retrieved from memory.

At step 408, the density comparison value retrieved at step 404, 406 or407 is compared to the average density represented by the output ofsensor S1. The result of this comparison is evaluated at step 409 todetermine whether the output of sensor S1 identifies a doubling of billsfor the particular denomination of bill determined at step 401. If theanswer is negative, the system returns to the main program. If theanswer is affirmative, step 410 then compares the retrieved densitycomparison value to the average density represented by the output of thesecond sensor S2. The result of this comparison is evaluated at step 411to determine whether the output of sensor S2 identifies a doubling ofbills. Affirmative answers at both step 409 and step 411 results in thesetting of a “doubles error” flag at step 412, and the system thenreturns to the main program. The above doubles detection routine isdescribed in more detail in U.S. Pat. No. 5,295,196 which isincorporated herein by reference. While the routine described above usessecond characteristic information (density) to detect doubles, the aboveroutine may be modified to authenticate bills based on their density,for example in a manner similar to that described in connection withTable 1.

Referring now to FIGS. 18a-18 c, there is shown a side view of oneembodiment of a discrimination and authentication unit according to thepresent invention, a top view of the embodiment of FIG. 18a along thedirection 18B, and a top view of the embodiment of FIG. 18a along thedirection 18C, respectively. An ultraviolet (“UV”) light source 422illuminates a document 424. Depending upon the characteristics of thedocument, ultraviolet light may be reflected off the document and/orfluorescent light may be emitted from the document. A detection system426 is positioned so as to receive any light reflected or emitted towardit but not to receive any UV light directly from the light source 422.The detection system 426 comprises a UV sensor 428, a fluorescencesensor 430, filters, and a plastic housing. The light source 422 and thedetection system 426 are both mounted to a printed circuit board 432.The document 424 is transported in the direction indicated by arrow A bya transport system (not shown). The document is transported over atransport plate 434 which has a rectangular opening 436 in it to permitpassage of light to and from the document. In one embodiment of thepresent invention, the rectangular opening 436 is 1.375 inches (3.493cm) by 0.375 inches (0.953 cm). To minimize dust accumulation onto thelight source 422 and the detection system 426 and to prevent documentjams, the opening 436 is covered with a transparent UV transmittingacrylic window 438. To further reduce dust accumulation, the UV lightsource 422 and the detection system 426 are completely enclosed within ahousing (not shown) comprising the transport plate 434.

Referring now to FIG. 19, there is shown a functional block diagramillustrating one embodiment of a discrimination and authentication unitaccording to the present invention. FIG. 19 shows an UV sensor 442, afluorescence sensor 444, and filters 446, 448 of a detection system suchas the detection system 426 of FIG. 18a. Light from the document passesthrough the filters 446, 448 before striking the sensors 442, 444,respectively. An ultraviolet filter 446 filters out visible light andpermits UV light to be transmitted and hence to strike UV sensor 442.Similarly, a visible light filter 448 filters out UV light and permitsvisible light to be transmitted and hence to strike fluorescence sensor444. Accordingly, UV light, which has a wavelength below 400 nm, isprevented from striking the fluorescence sensor 444 and visible light,which has a wavelength greater than 400 nm, is prevented from strikingthe UV sensor 442. In one embodiment the UV filter 446 transmits lighthaving a wavelength between about 260 nm and about 380 nm and has a peaktransmittance at 360 nm. In one embodiment, the visible light filter 448is a blue filter and preferably transmits light having a wavelengthbetween about 415 nm and about 620 nm and has a peak transmittance at450 nm. The above preferred blue filter comprises a combination of ablue component filter and a yellow component filter. The blue componentfilter transmits light having a wavelength between about 320 nm andabout 620 nm and has a peak transmittance at 450 nm. The yellowcomponent filter transmits light having a wavelength between about 415nm and about 2800 nm. Examples of suitable filters are UG1 (UV filter),BG23 (blue bandpass filter), and GG420 (yellow longpass filter), allmanufactured by Schott. In one embodiment the filters are about 8 mm indiameter and about 1.5 mm thick.

The UV sensor 442 outputs an analog signal proportional to the amount oflight incident thereon and this signal is amplified by amplifier 450 andfed to a microcontroller 452. Similarly, the fluorescence sensor 444outputs an analog signal proportional to the amount of light incidentthereon and this signal is amplified by amplifier 454 and fed to amicrocontroller 452. Analog-to-digital converters 456 within themicrocontroller 452 convert the signals from the amplifiers 450, 454 todigital and these digital signals are processed by the software of themicrocontroller 452. The UV sensor 442 may be, for example, anultraviolet enhanced photodiode sensitive to light having a wavelengthof about 360 nm and the fluorescence sensor 444 may be a blue enhancedphotodiode sensitive to light having a wavelength of about 450 nm. Suchphotodiodes are available from, for example, Advanced Photonix, Inc.,Massachusetts. The microcontroller 452 may be, for example, a Motorola68HC 16.

The exact characteristics of the sensors 442, 444 and the filters 446,448 including the wavelength transmittance ranges of the above filtersare not as critical to the present invention as the prevention of thefluorescence sensor from generating an output signal in response toultraviolet light and the ultraviolet sensor from generating an outputsignal in response to visible light. For example, instead of, or inaddition to, filters, a authentication system according to the presentinvention may employ an ultraviolet sensor which is not responsive tolight having a wavelength longer than 400 nm and/or a fluorescencesensor which is not responsive to light having a wavelength shorter than400 nm.

Calibration potentiometers 458, 460 permit the gains of amplifiers 450,454 to be adjusted to appropriate levels. Calibration may be performedby positioning a piece of white fluorescent paper on the transport plate434 so that it completely covers the rectangular opening 436 of FIG. 4a.The potentiometers 458, 460 may then be adjusted so that the output ofthe amplifiers 450, 454 is 5 volts. Alternatively, calibration may beperformed using genuine currency such as a piece of genuine U.S.currency. Potentiometers 458 and 460 may be replaced with electronicpotentiometers located, for example, within the microcontroller 452.Such electronic potentiometers may permit automatic calibration based onthe processing of a single genuine document or a plurality of documentsas will be described below.

The implementation of one embodiment of a discrimination andauthentication unit according to the present invention as illustrated inFIG. 19 with respect to the authentication of U.S. currency will now bedescribed. As discussed above, it has been determined that genuineUnited States currency reflects a high level of ultraviolet light anddoes not fluoresce under ultraviolet illumination. It has also beendetermined that under ultraviolet illumination counterfeit United Statescurrency exhibits one of the four sets of characteristics listed below:

1) Reflects a low level of ultraviolet light and fluoresces;

2) Reflects a low level of ultraviolet light and does not fluoresce;

3) Reflects a high level of ultraviolet light and fluoresces;

4) Reflects a high level of ultraviolet light and does not fluoresce .

Counterfeit bills in categories (1) and (2) may be detected by acurrency authenticator employing an ultraviolet light reflection testaccording to one embodiment of the present invention. Counterfeit billsin category (3) may be detected by a currency authenticator employingboth an ultraviolet reflection test and a fluorescence test according toanother embodiment of the present invention. Only counterfeits incategory (4) are not detected by the authenticating methods of thepresent invention.

According to one embodiment of the present invention, fluorescence isdetermined by any signal that is above the noise floor. Thus, theamplified fluorescent sensor signal 462 will be approximately 0 voltsfor genuine U.S. currency and will vary between approximately 0 and 5volts for counterfeit bills depending upon their fluorescentcharacteristics. Accordingly, an authenticating system according to oneembodiment of the present invention will reject bills when signal 462exceeds approximately 0 volts.

According to one embodiment of the discrimination unit, a high level ofreflected UV light (“high UV”) is indicated when the amplified UV sensorsignal 464 is above a predetermined threshold. The high/low UV thresholdis a function of lamp intensity and reflectance. Lamp intensity candegrade by as much as 50% over the life of the lamp and can be furtherattenuated by dust accumulation on the lamp and the sensors. The problemof dust accumulation is mitigated by enclosing the lamp and sensors in ahousing as discussed above. An authenticating system according to oneembodiment of the present invention tracks the intensity of the UV lightsource and readjusts the high/low threshold accordingly. The degradationof the UV light source may be compensated for by periodically feeding agenuine bill into the system, sampling the output of the UV sensor, andadjusting the threshold accordingly. Alternatively, degradation may becompensated for by periodically sampling the output of the UV sensorwhen no bill is present in the rectangular opening 436 of the transportplate 434. It is noted that a certain amount of UV light is alwaysreflected off the acrylic window 438. By periodically sampling theoutput of the UV sensor when no bill is present, the system cancompensate for light source degradation. Furthermore, such samplingcould also be used to indicate to the operator of the system when theultraviolet light source has burned out or otherwise requiresreplacement. This may be accomplished, for example, by means of adisplay reading or an illuminated light emitting diode (“LED”). Theamplified ultraviolet sensor signal 464 will initially vary between 1.0and 5.0 volts depending upon the UV reflectance characteristics of thedocument being scanned and will slowly drift downward as the lightsource degrades. In an alternative embodiment to one embodiment whereinthe threshold level is adjusted as the light source degrades, thesampling of the UV sensor output may be used to adjust the gain of theamplifier 450 thereby maintaining the output of the amplifier 450 at itsinitial levels.

It has been found that the voltage ratio between counterfeit and genuineU.S. bills varies from a discernible 2-to-1 ratio to a non-discernibleratio. According to one embodiment of the present invention a 2-to-1ratio is used to discriminate between genuine and counterfeit bills. Forexample, if a genuine U.S. bill generates an amplified UV output sensorsignal 464 of 4.0 volts, documents generating an amplified UV outputsensor signal 464 of 2.0 volts or less will be rejected as counterfeit.As described above, this threshold of 2.0 volts may either be lowered asthe light source degrades or the gain of the amplifier 450 may beadjusted so that 2.0 volts remains an appropriate threshold value.

The determination of whether the level of UV reflected off a document ishigh or low is made by sampling the output of the UV sensor at a numberof intervals, averaging the readings, and comparing the average levelwith the predetermined high/low threshold. Alternatively, a comparisonmay be made by measuring the amount of UV light reflected at a number oflocations on the bill and comparing these measurements with thoseobtained from genuine bills. Alternatively, the output of one or more UVsensors may be processed to generate one or more patterns of reflectedUV light and these patterns may be compared to the patterns generated bygenuine bills. Such a pattern generation and comparison technique may beperformed by modifying an optical pattern technique such as thatdisclosed in U.S. Pat. No. 5,295,196 incorporated herein by reference inits entirety or in U.S. patent application Ser. No. 08/287,882 filedAug. 9, 1994 for a “Method and Apparatus for Document Identification,”now issued as U.S. Pat. No. 5,652,802, incorporated herein by referencein its entirety.

The presence of fluorescence may be performed by sampling the output ofthe fluorescence sensor at a number of intervals. However, in oneembodiment, a bill is rejected as counterfeit U.S. currency if any ofthe sampled outputs rise above the noise floor. However, the alternativemethods discussed above with respect to processing the signal or signalsof a UV sensor or sensors may also be employed, especially with respectto currencies of other countries or other types of documents which mayemploy as security features certain locations or patterns of fluorescentmaterials.

The present invention may include means, such as a display, to indicateto the operator the reasons why a document has been rejected, e.g.,messages such as “UV FAILURE” or “FLUORESCENCE FAILURE.” The presentinvention may also permit the operator to selectively choose to activateor deactivate either the UV reflection test or the fluorescence test orboth. A currency authenticating system according to the presentinvention may also be provided with means for adjusting thesensitivities of the UV reflection and/or fluorescence test, forexample, by adjusting the respective thresholds. For example, in thecase of U.S. currency, a system according to the present invention maypermit the high/low threshold to be adjusted, for example, either inabsolute voltage terms or in genuine/suspect ratio terms.

The UV and fluorescence authentication test may be incorporated intovarious document handlers such as currency counters and/or currencydenomination discriminators such as that disclosed in connection withFIG. 15 and U.S. Pat. No. 5,295,196 incorporated herein by reference inits entirety. Likewise, the magnetic authentication tests describedabove may likewise be incorporated in such counters and/ordiscriminators. In such systems, calibration may be performed byprocessing a stack of genuine documents. An example of a method ofcalibrating such a device will now be discussed.

As mentioned above, the acrylic window 438 reflects a certain amount ofUV light even when no bill is present. The amount of UV light reflectedin the absence of bills is measured. A stack of genuine bills may thenbe processed with the potentiometer 458 set to some arbitrary value andthe resulting UV readings averaged. The difference between the averagereading and the reading made in the absence of bills may then becalculated. The potentiometer 458 may then be adjusted so that theaverage reading would be at least 0.7 volts greater then the no billreading. It is also desirable to adjust the potentiometer 458 so thatthe amplifier 450 operates around the middle of its operating range. Forexample, if a reading of 1.0 volt results when no bills are present andan average reading of 3.0 volts results when a stack of genuine billsare processed, the resulting difference is 2.0 volts which is greaterthan 0.7 volts. However, it is desirable for the amplifier to beoperating in the range of about 2.0 to 2.5 volts and preferably at about2.0 volts. Thus in the above example, the potentiometer 458 may be usedto adjust the gain of the amplifier 450 so that an average reading of2.0 volts would result. Where potentiometer 458 is an electronicpotentiometer, the gain of the amplifier 450 may be automaticallyadjusted by the microcontroller 452. In general, when the averagereading is too high the potentiometer is adjusted to lower the resultingvalues to the center of the operating range of the amplifier and viceversa when the average reading is too low.

According to another embodiment of the present invention, the operatorof a document processing system is provided with the ability to adjustthe sensitivity of a UV reflection test, a fluorescence test, and amagnetic test. For example, a note counter embodying one embodiment ofthe present invention may provide the operator the ability to set theauthentication tests to a high or a low sensitivity. For example, thenote counter may be provided with a set up mode which enables theoperator to adjust the sensitivities for each of the above tests forboth the high and the low modes. This may be achieved throughappropriate messages being displayed on, for example, display 282 ofFIG. 15 and the input of selection choices via an input device such as akeyboard or buttons. In one embodiment, the device permits the operatorto adjust the UV test, the fluorescent test, and the magnetic test in arange of sensitivities 1-7, with 7 being the most sensitive, or to turneach test off The device permits setting the sensitivity as describedabove for the three authentication tests for both a low sensitivity (lowdenomination) mode and a high sensitivity (high denomination) mode. Theabove setting options are summarized in Table 2.

TABLE 2 Fluorescent Test Magnetic Test Mode UV Test SensitivitySensitivity Sensitivity High off, 1-7 off, 1-7 off, 1-7 Low off, 1-7off, 1-7 off, 1-7

According to an alternate embodiment, the above high/low modes arereplaced with denomination modes, for example, one for each of severaldenominations of currency (e.g., $1, $2, $5, $10, $20, $50 and $100).For each denomination, the sensitivity of the three tests may beadjusted between 1-7 or off. According to one embodiment for operatormanually selects either the high or low mode or the appropriatedenomination mode based on the values of the notes to be processed. Thismanual mode selection system may be employed in, for example, either anote counter or a currency denomination discriminator. According toanother embodiment the document processing system automatically selectseither the high or low mode or the appropriate denomination mode basedon the values of the notes being processed. This automatic modeselection system may be employed in systems capable of identifying thedifferent values or kinds of documents, for example, a currencydenomination discriminator.

Accordingly, in the low mode or for low denomination modes (e.g., $1,$2) the three tests may be set to relatively low sensitivities (e.g., UVtest set at 2, fluorescent test set at 5, and magnetic test set at 3).Conversely, in the high mode or for high denomination modes (e.g., $50,$100) the three tests may be set to relatively high sensitivies (e.g.,UV test set at 5, fluorescent test set at 6, and magnetic test set at7). In this way, authentication sensitivity may be increased whenprocessing high value notes where the potential harm or risk in notdetecting a counterfeit may be greater and may be decreased whenprocessing low value notes where the potential harm or risk in notdetecting a counterfeit is lesser and the annoyance of wrongly rejectinggenuine notes is greater. Also the UV, fluorescent, and/or magneticcharacteristics of genuine notes can vary due to number of factors suchwear and tear or whether the note has been washed (e.g., detergents). Asa result, the fluorescent detection of genuine U.S. currency, forexample, may yield readings of about 0.05 or 0.06 volts.

The UV and fluorescent thresholds associated with each of the sevensensitivity levels may be set for example, as shown in Table 3.

TABLE 3 Sensitivity Level UV Test (Volts) Fluorescent Test (Volts) 1 0.20.7 2 0.3 0.6 3 0.4 0.5 4 0.5 0.3 5 0.55 0.2 6 0.6 0.15 7 0.7 0.1

In performing the UV test according to one embodiment, the no billreflectance value is subtracted from resultion UV reflectance voltagesassociated with the scanning of a particular bill, and this differenceis compared against the approiated threshold value such as those inTable 3 in determining whether to reject a bill.

According to one embodiment, the potentiometer 460 associated with thefluorescence detector 204 is calibrated by processing a genuine note orstack of notes, as described above in connection with the calibration ofthe UV detector and adjusted so that a reading of near 0 volts (e.g.,about 0.1 volt) results. Magnetic calibration may be performed, forexample, manually in conjunction with the processing of a genuine billof known magnetic characteristics and adjusting the magnetic sensor tonear the center of its range.

Upon a bill failing one or more of the above tests, an appropriate errormessage may be displayed such as “Suspect Document U—” for failure ofthe UV reflection test, “Suspect Document -F-” for failure of thefluorescent test, “Suspect Document—M” for failure of the magnetic test,or some combination thereof when more than one test is failed (e.g.,“Suspect Document UF-” for failure of both the UV reflection test andthe fluorescent test).

New security features are being added to U.S. currency beginning withthe 1996 series $100 bills. Subsequently, similar features will be addedto other U.S. denominations such as the $50 bill, $20 bill, etc. Some ofthe new security features include the incorporation into the bills ofsecurity threads that fluoresce under ultraviolet light. For example,the security threads in the 1996 series $100 bills emit a red glow whenilluminated by ultraviolet. The color of light illuminated from securitythreads under ultraviolet light will vary by denomination, for example,with the $100 notes emitting red light and the $50 notes emitting, forexample, blue light or purple light.

Additionally, the location of the thread within the bill can be used asa security feature. For example, the security threads in all $100 billsare located in the same position. Furthermore, the location of thesecurity threads in other denominations will be the same by denominationand will vary among several denominations. For example, the location ofsecurity threads in $10s, $20s, $50, and $100 may all be distinct.Alternatively, the location may be the same in the $20s and the $100sbut different from the location of the security threads in the $50s.

The ultraviolet system described above in connection with FIGS. 18 and19 may be modified to take advantage of this feature. Referring to FIG.20, a bill 330 is shown indicating three possible locations 332 a-332 cfor security threads in genuine bills depending on the denomination ofthe bill. Fluorescent light detectors 334 a-334 c are positioned overthe possible acceptable locations of fluorescing security threads. Insystems designed to accept bills fed in either the forward or thereverse direction identical detectors are positioned over the samelocations on each half of the bill. For example, sensors 334 c arepositioned a distance d₅ to the left and right of the center of the bill330. Likewise, sensors 334 b are positioned a distance d₆ to the leftand right of the center of the bill 330 while sensors 334 a arepositioned a distance d₇ to the left and right of the center of the bill330. Additional sensors may be added to cover additional possible threadlocations.

These sensors may be designed to detect a particular color of lightdepending on their location. For example, say location 332 b correspondsto the location of security threads in genuine $100 bills and location332 c corresponds to the location of security threads in genuine $50bills. Furthermore, if the security threads in $100 bills emit red lightunder ultraviolet light excitation and the security threads in $50 billsemit blue light under ultraviolet light excitation, then sensor 334 bmay be particularly designed to detect red light and sensor 334 c may bedesigned to detect blue light. Such sensors may employ filters whichpass red and blue light, respectfully, while screening out light ofother frequencies. Accordingly, for example, sensor 334 b will respondto a security thread located at location 332 b that emits red lightunder ultraviolet light excitation but not to a security thread atlocation 332 b that emits blue light.

Sensors 334 a-334 c may include separate sources of ultraviolet light orone or more separate ultraviolet light sources may be provided toilluminate the bill or portions of the bill, either on the same side ofthe bill as the sensors or on the opposite side of the bill. Thesesensors may be arranged along the same axis or, alternatively, may bestaggered upstream and downstream relative to each other. These sensorsmay be arranged all on the same side of the bill or some on one side ofthe bill and some on the other. Alternatively, for one or more locations332 a-332 c sensors may be placed on both sides of the bill. This dualsided embodiment would be beneficial in detecting counterfeits made byapplying an appropriate fluorescing material on the surface of a bill.Alternatively, a combination of normal lighting and ultraviolet lightingmay be employed but at different times to detect for the presence of acolored line applied to the surface of a bill visible in normallighting. According to such an embodiment, no colored thread should bedetected under normal lighting and an appropriate colored thread in anappropriate position must be detected under ultraviolet lighting.

Additionally, the authentication technique described above in connectionwith FIGS. 18 and 19 may be employed in areas where no fluorescingsecurity threads might be located, for example, near the center of thebill, such that the detection of fluorescent light would indicate acounterfeit bill as would the absence of a high level of reflectedultraviolet light.

Alternatively or additionally, sensors may be employed to detect billsor security threads printed or coated with thermochromic materials(materials that change color with a change in temperature. Examples ofthreads incorporating thermochromic materials are described in U.S. Pat.No. 5,465,301 incorporated herein by reference. For example, a securitythread may appear in one color at ambient temperatures under transmittedlight and may appear in a second color or appear colorless at or abovean activation temperature or vice versa. Alternatively, bills may beprinted and/or coated with such thermochromic materials. Such bills mayor may not include security threads and any included security threadsmay or may not also be printed or coated with thermochromatic materials.To detect for the proper characteristics of bills containing suchthermochromatic materials and/or containing threads employing suchthermochromic materials, the above described embodiments may be alteredto scan a bill at different temperatures. For example, a bill couldfirst be scanned at ambient temperatures, and then be transporteddownstream where the temperature of the bill is raised to or above anactivation temperature and scanned again at the higher temperature. Forexample, FIG. 20 could be modified to employ two sets of pairs ofsensors 334 a-c, one set downstream of the other with the downstreamsensors be located in a region where the temperature is evaluatedrelative to the temperature of the region where the first set of sensorsare located. A bill adjacent to the first and second sets of sensors 334a-c may be illuminated either with visible light or ultraviolet light(if the thermochromic material contains materials whose fluorescentcharacteristics alter with changes in temperature). Accordingly, thepresence of the appropriate color or absence of color may be detectedfor the different temperatures and the detected information may be usedto authenticate and/or denominate the bill.

The magnetic characteristics of 1996 series $100 bills also incorporateadditional security features. Referring to FIG. 21, several areas of thebill 340 are printed using magnetic ink, such as areas A-K.Additionally, in some areas the strength of the magnetic field isstronger than it is in areas A-K. These strong areas of magnetics areindicated, for example, at 344 a and 334 b. Some areas, such as area 346contain magnetic ink that is more easily detected by scanning the billalong one dimension of the bill than the other. For example, a strongmagnetic field is detected by scanning over area 346 in the long or widedimension of the bill 340 and a weak field is detected by scanning area346 in the narrow dimension of the bill 340. The remaining areas of thebill are printed with non-magnetic ink.

Some of these magnetic characteristics vary by denomination. Forexample, in a new series $50 note, areas A′, B′, C′, E′, F′, G′ and K′may be printed with magnetic ink and areas 354 a and 354 b may exhibiteven stronger magnetic characteristics. Accordingly, the non-magneticareas also vary relative to the $100 bill.

The use of magnetic ink in some areas of bills of one denomination andin other areas of bills of other denominations is referred to asmagnetic zone printing. Additionally, magnetics are employ as a securityfeature by using ink exhibiting magnetic properties in some areas andink that does not exhibit magnetic properties in adjacent areas whereinboth the ink exhibiting and the ink not exhibiting magnetic propertiesappear visually the same. For example, the upper left-hand numerical 100appears visually to be printed with the same ink. Nonetheless, the “10”are printed with ink not exhibiting magnetic properties while the last“0” is printed with ink that does exhibit magnetic properties. Forexample, see area F of FIG. 21.

Examples of arrangements of magnetic sensors that may be used to detectthe above described magnetic characteristics are illustrated in FIGS. 23and 24. Additionally, the arrangements described above may also beemployed such as those depicted in FIGS. 4f, 6-10, 12, and 15. FIG. 23illustrates bill 360 being transported past magnetic sensors 364 a-d inthe narrow dimension of the bill. FIG. 24 illustrates bill 370 beingtransported past magnetic sensors 374 a-c in the long dimension of thebill. Magnetic scanning using these sensors may be performed in a mannersimilar to that described above in connection with optical scanning. Forexample, each sensor may be used to generate a magnetically scannedpattern such as that depicted in FIG. 14. Such patterns may be comparedto stored master magnetic patterns. The scanning may be performed inconjunction with timing signals provided by an encoder such as describedabove in connection with optical scanning.

Alternatively, instead of generating scanned magnetic patterns, thepresence or absence of magnetic ink in various areas may be detected andcompared the stored master information coinciding with several areaswhere magnetic ink is expected and not expected on genuine bills ofvarious denominations. For example, the detection of magnetic ink atarea F is be expected for a $100 bill but might not be for a $50 billand vice versa for area F′. See FIGS. 21 and 22. Accordingly, thedetected magnetic information may be used to determine the denominationof a bill and/or to authenticate that a bill which has been determinedto have a given denomination using a different test, such as via acomparison of an optically scanned pattern with master optical patterns,has the magnetic properties expected for that given denomination. Timingsignals provided by an encoder such as described above in connectionwith optical scanning may be employed in detecting magneticcharacteristics of specific areas of bills.

Additionally, for magnetic properties that are the same for all bills,such as the presence or absence of magnetic ink in a given location,such as the absence of magnetic ink in area 347 in FIGS. 21 and 22, maybe used as a general test to authenticate whether a given bill has themagnetic properties associated with genuine U.S. currency.

Alternatively, magnetic sensors 364 a-d, 366 a-g, and 374 a-c may detectthe magnitude of magnetic fields at various locations of a bill andperform bill authentication or denomination based thereon. For example,the strength of magnetic fields may be detected at areas J, 344 a, and348. See FIG. 21. In a genuine $100 bill, no magnetic ink is present atarea 348. One test to call a bill to be a $100 bill or authenticate thata bill is a $100 bill would be to compare the relative levels ofmagnetic field strength detected at these areas. For example, a bill maybe determined genuine if a greater signal is generated by scanning area344 a than area J which in turn is greater than for area 348.Alternatively, generated signals may be compared against expectedratios, for example, that the signal for area 344 a is greater than 1.5times the signal for area J. Alternatively, the signals generated byscanning various locations may be compared to reference signalsassociated with genuine bills for those locations.

Another denominating or authenticating technique may be understood withreference to area 346 of FIG. 21. It will be recalled that for this areaof a $100 bill a strong magnetic signal is generated when this area isscanned in the long dimension of the bill and a weak signal is generatedwhen this area is scanned in the narrow dimension. Accordingly, thesignals generated by sensors 364 and 374 for this area can be comparedto each other and/or to different threshold levels to determine whethera particular bill being scanned has these properties. This informationmay be then used to assist in calling the denomination of the bill orauthenticating a bill whose denomination has previously been determined.

FIGS. 25-47 are flowcharts illustrating several methods for usingoptical. magnetic, and security thread information to denominate andauthenticate bills. These methods may be employed with the variouscharacteristic information detection techniques described aboveincluding, for example, those employing visible and ultraviolet lightand magnetics including, for example, those for detecting variouscharacteristics of security threads.

FIG. 25 is a flowchart illustrating the steps performed in opticallydetermining the denomination of a bill. At step 500, a bill is opticallyscanned and an optical pattern is generated. At step 502 the scannedoptical pattern is compared to one or more stored master opticalpatterns. One or more master optical patterns are stored for eachdenomination that a system employing the method of FIG. 25 is designedto discriminate. At step 504 it is determined whether as a result of thecomparison of step 502 the scanned optical pattern sufficiently matchesone of the stored master optical patterns. For example, the comparisonof patterns may yield a correlation number for each of the stored masterpatterns. To sufficiently match a master pattern, it may be requiredthat the highest correlation number be greater than a threshold value.An example of such a pattern comparison method is described in moredetail in U.S. Pat. No. 5,295,196 incorporated herein by reference. Ifthe scanned pattern does not sufficiently match one of the stored masterpatterns, a no call code is generated at step 506. Otherwise, if thescanned pattern does sufficiently match one of the stored masterpatterns, the denomination associated with the matching master opticalpattern is indicated as the denomination of the scanned bill at step508.

FIG. 26 is a flowchart illustrating the steps performed in determiningthe denomination of a bill based on the location of a security thread.At step 510, a bill is scanned for the presence of a security thread.The presence of a security thread may be detected using a number oftypes of sensors such as optical sensors using transmitted and/orreflected light, magnetic sensors, and/or capacitive sensors. See, forexample, U.S. Pat. Nos. 5,151,607 and 5,122,754. If a thread is notpresent as determined at step 512, a suspect code may be issued at step514. This suspect code may indicate that no thread was detected if thislevel of detail is desirable. The lack of the presence of a threadresulting in a suspect code is particularly useful when all bills to beprocessed are expected to have a security thread therein. In othersituations, the absence of a security thread may indicate that a scannedbill belongs to one or more denominations but not others. For example,assuming security threads are present in all genuine U.S. bills between$2 and $100 dollars, but not in genuine $1 bills, the absence of asecurity thread may be used to indicate that a scanned bill is a $1bill. According to one embodiment, where it is determined that nosecurity thread is present, a bill is preliminary indicated to be a $1bill. Preferably, some additional test is performed to confirm thedenomination of the bill such as the performance of the opticaldenominating methods described above in FIG. 25. The opticaldenominating steps may be performed before or after the thread locatingtest.

If at step 512 it is determined that a security thread is present, thelocation of the detected security thread is then compared with masterthread locations associated with genuine bills at step 516. At step 518it is determined whether as a result of the comparison at step 516 thedetected thread location matches one of the stored master threadlocations. If the detected thread location does not sufficiently matchone of the stored master thread locations, an appropriate suspect codeis generated at step 520. This suspect code may indicate that detectedthread was not in an acceptable location if such information isdesirable. Otherwise, if the detected thread location does sufficientlymatch one of the stored master thread locations, the denominationassociated with the matching master thread location is indicated as thedenomination of the scanned bill at step 522.

FIG. 27 is a flowchart illustrating the steps performed in determiningthe denomination of a bill based on the fluorescent color of a securitythread. For example, as described above 1996 series $100 bills containsecurity threads which emit red light when illuminated with ultravioletlight. At step 524, a bill is illuminated with ultraviolet light. Atstep 526, the bill is scanned for the presence of a security thread andcolor of any fluorescent light emitted by a security thread that ispresent. The presence of a security thread may be detected as describedabove in connection with FIG. 26. Alternatively, the presence of asecurity thread may be detected before the bill is illuminated withultraviolet light and scanned for fluorescent light. If a thread is notpresent as determined at step 528, an appropriate suspect code may beissued at step 530. The considerations discussed above in connectionwith FIG. 26 concerning genuine bills which do not contain securitythreads are applicable here as well. If at step 528 it is determinedthat a security thread is present, the color of any fluorescent lightemitted by the detected security thread is then compared with masterthread fluorescent colors associated with genuine bills at step 532. Ifat step 532, the detected thread fluorescent light does not match one ofthe stored master thread fluorescent colors, an appropriate suspect codeis generated at step 534. Otherwise, if the detected thread fluorescentcolor does sufficiently match one of the stored master threadfluorescent colors, the denomination associated with the matching masterthread color is indicated as the denomination of the scanned bill atstep 536. The sensors used to detect fluorescent light may be designedonly to respond to light corresponding to an appropriate master color.This may be accomplished, for example, by employing light filters thatpermit only light having a frequency of a genuine color to reach a givensensor. Sensors such as those discussed in connection with FIGS. 18-20may be employed to detect appropriate fluorescent thread colors.

FIG. 28 is a flowchart illustrating the steps performed in determiningthe denomination of a bill based on the location and fluorescent colorof a security thread. FIG. 28 essentially combines the steps of FIGS. 26and 27. At step 540, the bill is scanned for the presence, location, andfluorescent color of a security thread. The presence of a securitythread may be detected as described above in connection with FIG. 26. Ifa thread is not present as determined at step 542, an appropriatesuspect code may be issued at step 544. The considerations discussedabove in connection with FIG. 26 concerning genuine bills which do notcontain security threads are applicable here as well. If at step 542 itis determined that a security thread is present, the detected threadlocation is compared with master thread locations at step 546. If thelocation of the detected thread does not match a master thread location,an appropriate suspect code may be issued at step 548. If the locationof the detected thread does match a master thread location, the scannedbill can be preliminary indicated to have the denomination associatedwith the matching thread location at step 550. Next at step 552 it isdetermined whether the color of any fluorescent light emitted by thedetected security thread matches the master thread fluorescent colorassociated with a genuine bill of the denomination indicated at step550. If at step 552, the detected thread fluorescent light does notmatch the corresponding stored master thread fluorescent color for thepreliminary indicated denomination, an appropriate suspect code isgenerated at step 554. Otherwise, if the detected thread fluorescentcolor does sufficiently match the stored master thread fluorescent colorfor the preliminary indicated denomination, at step 556 the scanned billis indicated to be of the denomination indicated at step 550.

FIG. 29 is a flowchart illustrating the steps performed in magneticallydetermining the denomination of a bill. At step 558, a bill ismagnetically scanned and one or more magnetic patterns are generated.Alternatively, instead of generating magnetically scanned patterns, abill is magnetically scanned for the presence or absence of magnetic inkat one or more specific locations on the bill. Alternatively, instead ofsimply detecting whether magnetic ink is present at certain locations,the strength of magnetic fields may be measured at one or more locationson the bill. At step 560 the scanned magnetic information is compared tomaster magnetic information. One or more sets of master magneticinformation are stored for each denomination that a system employing themethods of FIG. 29 is designed to discriminate. For example, where oneor more scanned magnetic patterns are generated, such patterns arecompared to stored master magnetic patterns. Where, the presence orabsence of magnetic ink is detected at various locations on a bill, thisinformation is compared to the stored master magnetic informationassociated with the expected presence and absence of magnetic inkcharacteristics at these various locations for one or more denominationsof genuine bills. Alternatively, measured field strength information canbe compared to master field strength information. At step 562 it isdetermined whether as a result of the comparison of step 560 the scannedmagnetic information sufficiently matches one of sets of stored mastermagnetic information. For example, the comparison of patterns may yielda correlation number for each of the stored master patterns. Tosufficiently match a master pattern, it may be required that the highestcorrelation number be greater than a threshold value. An example of sucha method as applied to optically generated patterns is described in moredetail in U.S. Pat. No. 5,295,196 incorporated herein by reference. Ifthe scanned magnetic information does not sufficiently match the storedmaster magnetic information, an appropriate suspect code is generated atstep 564. Otherwise, if the scanned magnetic information doessufficiently match one of the sets of stored master magneticinformation, the denomination associated with the matching set of mastermagnetic information is indicated as the denomination of the scannedbill at step 566.

FIG. 30 is a flowchart illustrating the steps performed in opticallydenominating a bill and authenticating the bill based on thread locationand/or color information. At step 568, a bill is optically denominated,for example, according to the methods described above in connection withFIG. 25. Provided the denomination of the bill is optically determinedat step 568, the bill is then authenticated based on the location and/orcolor of the security thread in the bill at step 570. The authenticationstep 570 may be performed, for example, according to the methodsdescribed in connection with FIGS. 26-28. At step 570, however, thedetected thread location and/or color are only compared to master threadlocation and/or color information associated with the denominationdetermined in step 568. If the master thread location and/or color forthe denomination indicated in step 568 match (step 572) the detectedthread location and/or color for the bill under test, the bill isaccepted (at step 576) as being a bill having the denominationdetermined in step 568. Otherwise, an appropriate suspect code is issuedat step 574.

FIG. 31 is a flowchart illustrating the steps performed in denominatinga bill based on thread location and/or color information and opticallyauthenticating the bill. At step 578, a bill is denominated based onthread location and/or color information, for example, according to themethods described above in connection with FIGS. 26-28. Provided thedenomination of the bill is determined at step 578, the bill is thenoptically authenticated at step 580. The optical authentication step 580may be performed, for example, according to the methods described inconnection with FIG. 25. At step 580, however, the scanned opticalpattern or information is only compared to master optical pattern orpatterns or information associated with the denomination determined instep 578. If the master optical pattern or patterns or information forthe denomination indicated in step 578 match (step 582) the scannedoptical pattern or information for the bill under test, the bill isaccepted (at step 586) as being a bill having the denominationdetermined in step 578. Otherwise, an appropriate suspect code is issuedat step 584.

FIG. 32 is a flowchart illustrating the steps performed in opticallydenominating a bill and magnetically authenticating the bill. At step588, a bill is optically denominated, for example, according to themethods described above in connection with FIG. 25. Provided thedenomination of the bill is optically determined at step 588, the billis then magnetically authenticated at step 590. The magneticauthentication step 590 may be performed, for example, according to themethods described in connection with in FIG. 29. At step 590, however,the detected magnetic information is only compared to master magneticinformation associated with the denomination determined in step 588. Ifthe master magnetic information for the denomination indicated in step588 matches (step 592) the detected magnetic information for the billunder test, the bill is accepted (at step 596) as being a bill havingthe denomination determined in step 588. Otherwise, an appropriatesuspect code is issued at step 594.

FIG. 33 is a flowchart illustrating the steps performed in magneticallydenominating a bill and optically authenticating the bill. At step 598,a bill is magnetically denominated, for example, according to themethods described above in connection with FIG. 29. Provided thedenomination of the bill is magnetically determined at step 598, thebill is then optically authenticated at step 600. The opticalauthentication step 600 may be performed, for example, according to themethods described in connection with in FIG. 25. At step 600, however,the detected optical information (or pattern) is only compared to masteroptical information (or pattern or patterns) associated with thedenomination determined in step 598. If the master optical informationfor the denomination indicated in step 598 matches (step 602) thedetected optical information for the bill under test, the bill isaccepted (at step 606) as being a bill having the denominationdetermined in step 598. Otherwise, an appropriate suspect code is issuedat step 604.

FIG. 34 is a flowchart illustrating the steps performed in denominatinga bill both optically and based on thread location and/or colorinformation. At step 608, a bill is optically denominated, for example,according to the methods described above in connection with FIG. 25.Provided the denomination of the bill is optically determined at step608, the bill is then denominated based on the location and/or color ofthe security thread in the bill at step 610. The denominating step 610may be performed, for example, according to the methods described inconnection with FIGS. 26-28. At step 610, the denominating based ondetected thread location and/or color is performed independently of theresults of the optical denominating step 608. At step 612, thedenomination as determined optically is compared with the denominationas determined based on thread location and/or color. If both optical andthread based denominating steps indicate the same denomination, the billis accepted (at step 616) as being a bill having the denominationdetermined in steps 608 and 610. Otherwise, an appropriate suspect codeis issued at step 614. Alternatively, the order of steps 608 and 610 maybe reversed such that the bill is first denominated based on threadlocation and/or color and then optically denominated.

FIG. 35 is a flowchart illustrating the steps performed in denominatinga bill both optically and magnetically. At step 618, a bill is opticallydenominated, for example, according to the methods described above inconnection with FIG. 25. Provided the denomination of the bill isoptically determined at step 618, the bill is then denominatedmagnetically at step 620, for example, according to the methodsdescribed in connection with FIG. 29. At step 620, the magneticdenominating is performed independently of the results of the opticaldenominating step 618. At step 622, the denomination as determinedoptically is compared with the denomination as determined magnetically.If both optical and magnetic denominating steps indicate the samedenomination, the bill is accepted (at step 626) as being a bill havingthe denomination determined in steps 618 and 620. Otherwise, anappropriate suspect code is issued at step 624. Alternatively, the orderof steps 618 and 620 may be reversed such that the bill is firstmagnetically denominated and then optically denominated.

FIG. 36 is a flowchart illustrating the steps performed in denominatinga bill both magnetically and based on thread location and/or colorinformation. At step 628, a bill is magnetically denominated, forexample, according to the methods described above in connection withFIG. 29. Provided the denomination of the bill is magneticallydetermined at step 628, the bill is then denominated based on thelocation and/or color of the security thread in the bill at step 630.The denominating step 630 may be performed, for example, according tothe methods described in connection with FIGS. 26-28. At step 630, thedenominating based on detected thread location and/or color is performedindependently of the results of the magnetic denominating step 628. Atstep 632, the denomination as determined magnetically is compared withthe denomination as determined based on thread location and/or color. Ifboth magnetic and thread based denominating steps indicate the samedenomination, the bill is accepted (at step 636) as being a bill havingthe denomination determined in steps 628 and 630. Otherwise, anappropriate suspect code is issued at step 634. Alternatively, the orderof steps 628 and 630 may be reversed such that the bill is firstdenominated based on thread location and/or color and then magneticallydenominated.

FIG. 37 is a flowchart illustrating the steps performed in denominatinga bill optically, based on thread location and/or color information, andmagnetically. At step 638, a bill is optically denominated, for example,according to the methods described above in connection with FIG. 25.Provided the denomination of the bill is optically determined at step638, the bill is then denominated based on the location and/or color ofthe security thread in the bill at step 640. The denominating step 640may be performed, for example, according to the methods described inconnection with FIGS. 26-28. At step 640, the denominating based ondetected thread location and/or color is performed independently of theresults of the optical denominating step 638. Provided the denominationof the bill is determined at step 640, the bill is then denominatedmagnetically at step 642, for example, according to the methodsdescribed in connection with FIG. 29. At step 642, the magneticdenominating is performed independently of the results of thedenominating steps 638 and 640. At step 644, the denominations asdetermined optically, magnetically, and based on thread location and/orcolor are compared. If all denominating steps 638-642 indicate the samedenomination, the bill is accepted (at step 648) as being a bill havingthe denomination determined in steps 638-642. Otherwise, an appropriatesuspect code is issued at step 646. Alternatively, the order of steps638-642 may be rearranged. For example, a bill may be first denominatedoptically, then be denominated magnetically, and finally be denominatedbased on thread location and/or color. Alternatively, a bill may befirst denominated magnetically, then be denominated optically, andfinally be denominated based on thread location and/or color.Alternatively, a bill may be first denominated magnetically, then bedenominated based on thread location and/or color, and finally bedenominated optically. Alternatively, a bill may be first denominatedbased on thread location and/or color, and then be denominatedmagnetically, and finally be denominated optically. Alternatively, abill may be first denominated based on thread location and/or color, andthen be denominated optically, and finally be denominated magnetically.

FIG. 38 is a flowchart illustrating the steps performed in a methodwhereby a bill is denominated based on a first characteristic, thenauthenticated based on a second characteristic, and if the bill isauthenticated, then the bill is denominated again based on the secondcharacteristic. According to the flowchart of FIG. 38, at step 650, abill is optically denominated, for example, according to the methodsdescribed above in connection with FIG. 25. Provided the denomination ofthe bill is optically determined at step 650, the bill is thenmagnetically authenticated at step 652. The magnetic authentication step652 may be performed, for example, according to the methods described inconnection with in FIG. 29. At step 652, however, the detected magneticinformation is only compared to master magnetic information associatedwith the denomination determined in step 650. If the master magneticinformation for the denomination indicated in step 650 does notsufficiently match (step 654) the detected magnetic information for thebill under test, an appropriate suspect code is issued at step 656.Otherwise, the bill is denominated again (at step 658) but this timeusing magnetic information. If the magnetically determined denominationdoes not match (step 660) the optically determined denomination, anappropriate error code is issued at step 662. If the magneticallydetermined denomination does match (step 660) the optically determineddenomination, the denomination as determined at steps 650 and 658 isindicated as the denomination of the bill under test at step 664.

The method of FIG. 38 is advantageous in providing a high degree ofcertainty in the determination of the denomination of a bill whileshortening processing time when a bill fails an earlier test. Forexample, at step 650 a bill is optically denominated. If the bill cannot be called as a specific denomination under the optical test, a nocall code is issued such as at step 506 in FIG. 25 and thedenominating/authenticating process ends with respect to the bill. Ifthe bill is successfully optically denominated, the bill is thenauthenticated based on magnetic information at step 652. Processing timeis saved at this step by comparing, the scanned magnetic information forthe bill under test only with master magnetic information associatedwith the denomination as determined optically at step 650. If thescanned magnetic information does not sufficiently match the mastermagnetic information for that denomination, an appropriate suspect codeis issued and the denominating/authenticating process ends with respectto the bill. If the bill successfully passes the authentication step654, the bill is then denominated using the magnetic information. Herethe scanned magnetic information is compared to master magneticinformation for a number of denominations. It is then determined whichdenomination is associated with the master magnetic information thatbest matches the scanned magnetic information and this denomination iscompared with the optically determined denomination to verify that theyagree. For example, a bill may be optically determined to be a $100bill. The magnetic information employed may be magnetic patterns similarto the optically generated patterns described above and in U.S. Pat. No.5,295,196. At step 652, the scanned magnetic pattern is correlatedagainst the master magnetic pattern or patterns associated with $100bills. Assume, for example, that a correlation value of at least 850 isrequired to pass the authentication test. If the scanned magneticpattern yields a correlation of 860 when compared to the master magneticpattern or patterns associated with $100 bills, the bill then passes theauthentication step 654. At this point, the bill is magneticallydenominated independently of the results of the optical denominatingstep 650. This step ensures that the best match magnetically matches thebest match optically. For example, if at step 658, the highestcorrelation is 860 which is associated with a $100 bill master magneticpattern, then the magnetic denominating and optical denominating stepsboth point to a $100 bill and accordingly, the bill is indicated to be a$100 bill at step 664. However, if the highest correlation is 900 whichis associated with a $20 bill master magnetic pattern, then theoptically determined denomination and the magnetically determineddenomination disagree and an appropriate error message is issued at step662.

The method of FIG. 38 may be particularly useful in denominating andauthenticating bills of higher denominations such as $20, $50, and $100bills. The higher value of these notes may make it desirable toundertake the additional denominating steps 658-664. The method of FIG.38 could be modified so that if a bill were determined to be a $20, $50,or $100 at step 650 then the steps as indicated in FIG. 38 would befollowed. However, if a bill were determined to be a $1, $2, $5, or $10at step 650, then instead of magnetically denominating the bill at step658, the bill could be immediately accepted such as in FIG. 32.

FIG. 39 is a flowchart illustrating the steps performed in a methodwhereby a bill is denominated based on a first characteristic, thenauthenticated based on a second characteristic, and if the bill failsthe authentication test, then the bill is denominated again based on thesecond characteristic. According to the flowchart of FIG. 39, at step666, a bill is optically denominated, for example, according to themethods described above in connection with FIG. 25. Provided thedenomination of the bill is optically determined at step 666, the billis then magnetically authenticated at step 668. The magneticauthentication step 668 may be performed, for example, according to themethods described in connection with in FIG. 29. At step 668, however,the detected magnetic information is only compared to master magneticinformation associated with the denomination determined in step 666. Ifthe master magnetic information for the denomination indicated in step666 matches (step 670) the detected magnetic information for the billunder test, the bill is indicated (at step 672) to have the denominationas determined at step 666. Otherwise, the bill is denominated again (atstep 674) but this time using magnetic information. If the detectedmagnetic information sufficiently matches (step 676) any of the storedmaster magnetic information, an appropriate error code is issued at step678. Because the bill failed the test at step 670, if the scannedmagnetic information matches any of the stored master magneticinformation, the matching master magnetic information will be associatedwith a denomination other than the denomination determined optically atstep 666. Accordingly, at step 678, the magnetically determineddenomination differs from the optically determined denomination and anappropriate error code may be generated such as a no call codeindicating that the optical and magnetic tests resulted in differentdenomination determinations thus preventing the system from calling thedenomination of the bill under test. Such an error might be indicativeof a situation where the bill under test is a genuine bill that had itsoptical or magnetic appearance altered, for example, where a genuine $1bill was changed so that it appeared optically at least in part to belike a higher denomination bill such as a $20 bill. If the detectedmagnetic information does not match (step 676) any of the stored mastermagnetic information, an appropriate suspect code is issued at step 680.The error code at step 680 may indicate that the scanned bill does notmatch magnetically any of the stored master magnetic informationassociated with genuine bills.

The method of FIG. 39 is advantageous in that processing time is savedwhere a bill is determined to be genuine after passing two tests.Furthermore, when a bill fails the test at step 670, an additional testis performed to better define the suspect qualities of a bill which isrejected.

In FIGS. 38 and 39 the first characteristic is optical information andthe second characteristic is magnetic information. Alternatively, themethods of FIGS. 38 and 39 may be performed with other combinations ofcharacteristic information wherein the first and second characteristicinformation comprise a variety of characteristic information asdescribed above such as magnetic, optical, color, and thread basedinformation. Examples of such alternatives are discussed below inconnection with FIGS. 40-44. Alternatively, the methods of FIGS. 38 and39 may be performed utilizing first characteristic information todenominate a bill, then using second characteristic information toauthenticate the bill and finally denominating the bill again usingthird characteristic information. Again the variety of characteristicinformation described above such as magnetic, optical, color, and threadbased information may be employed in various combinations as first,second, and third characteristic information.

FIG. 40 is similar to FIG. 39 and is a flowchart illustrating the stepsperformed in a method whereby a bill is denominated based on a firstcharacteristic, then authenticated based on a second characteristic, andif the bill fails the authentication test, then the bill is denominatedagain based on the second characteristic. According to the flowchart ofFIG. 40, at step 682, a bill is denominated based on thread locationand/or color, for example, according to the methods described above inconnection with FIGS. 26-28. Provided the denomination of the bill isdetermined at step 682, the bill is then magnetically authenticated atstep 684. The magnetic authentication step 684 may be performed, forexample, according to the methods described in connection with in FIG.29. At step 684, however, the detected magnetic information is onlycompared to master magnetic information associated with the denominationdetermined in step 682. If the master magnetic information for thedenomination indicated in step 682 matches (step 686) the detectedmagnetic information for the bill under test, the bill is accepted andindicated (at step 688) to have the denomination as determined at step682. Otherwise, the bill is denominated again (at step 690) but thistime using magnetic information. If the detected magnetic informationsufficiently matches (step 692) any of the stored master magneticinformation, an appropriate error code is issued at step 696. Becausethe bill failed the test at step 686, if the scanned magneticinformation matches any of the stored master magnetic information, thematching master magnetic information will be associated with adenomination other than the denomination determined at step 682.Accordingly, at step 696, the magnetically determined denominationdiffers from the thread-based determined denomination and an appropriateerror code may be generated such as a no call code indicating that thethread-based and magnetic tests resulted in different denominationdeterminations thus preventing the system from calling the denominationof the bill under test. If the detected magnetic information does notmatch (step 692) any of the stored master magnetic information, anappropriate suspect code is issued at step 694. The error code at step694 may indicate that the scanned bill does not match magnetically anyof the stored master magnetic information associated with genuine bills.

FIG. 41 is also similar to FIG. 39 and is a flowchart illustrating thesteps performed in a method whereby a bill is denominated based on afirst characteristic, then authenticated based on a secondcharacteristic, and if the bill fails the authentication test, then thebill is denominated again based on the second characteristic. Accordingto the flowchart of FIG. 41, at step 698, a bill is opticallydenominated, for example, according to the methods described above inconnection with FIG. 25. Provided the denomination of the bill isdetermined at step 698, the bill is then authenticated based on threadlocation and/or color at step 700. The authentication step 700 may beperformed, for example, according to the methods described in connectionwith in FIGS. 26-28. At step 700, however, the detected threadinformation is only compared to master thread information associatedwith the denomination determined in step 698. If the master threadinformation for the denomination indicated in step 698 matches (step702) the detected thread information for the bill under test, the billis accepted and indicated (at step 704) to have the denomination asdetermined at step 698. Otherwise, the bill is denominated again (atstep 706) but this time using thread information. If the detected threadinformation matches (step 708) any of the stored master threadinformation, an appropriate error code is issued at step 712. Becausethe bill failed the test at step 702, if the thread-based informationmatches any of the stored master thread information, the matching masterthread information will be associated with a denomination other than thedenomination determined at step 698. Accordingly, at step 712, thethread-based determined denomination differs from the opticallydetermined denomination and an appropriate error code may be generatedsuch as a no call code indicating that the thread-based and opticaltests resulted in different denomination determinations thus preventingthe system from calling the denomination of the bill under test. If thedetected thread information does not match (step 708) any of the storedmaster thread information, an appropriate suspect code is issued at step710. The error code at step 710 may indicate that the threadcharacteristics of the scanned bill does not match any of the storedmaster thread information associated with genuine bills.

FIG. 42 is also similar to FIG. 39 and is a flowchart illustrating thesteps performed in a method whereby a bill is denominated based on afirst characteristic, then authenticated based on a secondcharacteristic, and if the bill fails the authentication test, then thebill is denominated again based on the second characteristic. Accordingto the flowchart of FIG. 42, at step 714, a bill is magneticallydenominated, for example, according to the methods described above inconnection with FIG. 29. Provided the denomination of the bill isdetermined at step 714, the bill is then authenticated based on threadlocation and/or color at step 716. The authentication step 716 may beperformed, for example, according to the methods described in connectionwith in FIGS. 26-28. At step 716, however, the detected threadinformation is only compared to master thread information associatedwith the denomination determined in step 714. If the master threadinformation for the denomination indicated in step 714 matches (step718) the detected thread information for the bill under test, the billis accepted and indicated (at step 720) to have the denomination asdetermined at step 714. Otherwise, the bill is denominated again (atstep 722) but this time using thread information. If the detected threadinformation matches (step 724) any of the stored master threadinformation, an appropriate error code is issued at step 728. Becausethe bill failed the test at step 718, if the thread-based informationmatches any of the stored master thread information, the matching masterthread information will be associated with a denomination other than thedenomination determined at step 714. Accordingly, at step 728, thethread-based determined denomination differs from the magneticallydetermined denomination and an appropriate error code may be generatedsuch as a no call code indicating that the thread-based and magnetictests resulted in different denomination determinations thus preventingthe system from calling the denomination of the bill under test. If thedetected thread information does not match (step 724) any of the storedmaster thread information, an appropriate suspect code is issued at step726. The error code at step 726 may indicate that the threadcharacteristics of the scanned bill does not match any of the storedmaster thread information associated with genuine bills.

FIG. 43 is similar to FIG. 38 and is a flowchart illustrating the stepsperformed in a method whereby a bill is denominated based on a firstcharacteristic, then authenticated based on a second characteristic, andif the bill is authenticated, then the bill is denominated again basedon the second characteristic. According to the flowchart of FIG. 43, atstep 730, a bill is magnetically denominated, for example, according tothe methods described above in connection with FIG. 29. Provided thedenomination of the bill is magnetically determined at step 730, thebill is then optically authenticated at step 732. The opticalauthentication step 732 may be performed, for example, according to themethods described in connection with in FIG. 25. At step 732, however,the detected optical information is only compared to master opticalinformation associated with the denomination determined in step 730. Ifthe master optical information for the denomination indicated in step730 does not sufficiently match (step 734) the detected opticalinformation for the bill under test, an appropriate suspect code isissued at step 736. Otherwise, the bill is denominated again (at step738) but this time using optical information. If the opticallydetermined denomination does not match (step 740) the magneticallydetermined denomination, an appropriate error code is issued at step742. If the optically determined denomination does match (step 740) themagnetically determined denomination, the denomination as determined atsteps 730 and 738 is indicated as the denomination of the bill undertest at step 744.

FIG. 44 is also similar to FIG. 38 and is a flowchart illustrating thesteps performed in a method whereby a bill is denominated based on afirst characteristic, then authenticated based on a secondcharacteristic, and if the bill is authenticated, then the bill isdenominated again based on the second characteristic. According to theflowchart of FIG. 44, at step 746, a bill is denominated based on threadlocation and/or color, for example, according to the methods describedabove in connection with FIGS. 26-28. Provided the denomination of thebill is determined at step 746, the bill is then optically authenticatedat step 748. The optical authentication step 748 may be performed, forexample, according to the methods described in connection with in FIG.25. At step 748, however, the detected optical information is onlycompared to master optical information associated with the denominationdetermined in step 746. If the master optical information for thedenomination indicated in step 746 does not sufficiently match (step750) the detected optical information for the bill under test, anappropriate suspect code is issued at step 752. Otherwise, the bill isdenominated again (at step 754) but this time using optical information.If the optically determined denomination does not match (step 756) thethread-based determined denomination, an appropriate error code isissued at step 758. If the optically determined denomination does match(step 740) the thread-based determined denomination, the denomination asdetermined at steps 746 and 754 is indicated as the denomination of thebill under test at step 760.

FIGS. 45 and 46 illustrate methods where for a bill to be accepted it isfirst denominated utilizing first characteristic information, thenauthenticated using second characteristic information, and finallyauthenticated again using third characteristic information.

According to the flowchart of FIG. 45, at step 762, a bill is opticallydenominated, for example, according to the methods described above inconnection with FIG. 25. Provided the denomination of the bill isoptically determined at step 762, the bill is then magneticallyauthenticated at step 764. The magnetic authentication step 764 may beperformed, for example, according to the methods described in connectionwith in FIG. 29. At step 764, however, the detected magnetic informationis only compared to master magnetic information associated with thedenomination determined in step 762. If the master magnetic informationfor the denomination indicated in step 762 matches (step 766) thedetected magnetic information for the bill under test, the bill is thenauthenticated based on thread location and/or color at step 768. Theauthentication step 768 may be performed, for example, according to themethods described in connection with in FIGS. 26-28. At step 768,however, the detected thread information is only compared to masterthread information associated with the denomination determined in step762. If the master thread information for the denomination indicated instep 762 matches (step 770) the detected thread information for the billunder test, the bill is accepted and indicated (at step 772) to have thedenomination as determined at step 762. Otherwise, the bill isdenominated again (at step 774) but this time using thread information.If the detected thread information matches (step 776) any of the storedmaster thread information, an appropriate error code is issued at step778. Because the bill failed the test at step 770, if the thread-basedinformation matches any of the stored master thread information, thematching master thread information will be associated with adenomination other than the denomination determined at step 762.Accordingly, at step 778, the thread-based determined denominationdiffers from the optically determined denomination and an appropriateerror code may be generated such as a no call code indicating that thethread-based and optical tests resulted in different denominationdeterminations thus preventing the system from calling the denominationof the bill under test. If the detected thread information does notmatch (step 776) any of the stored master thread information, anappropriate suspect code is issued at step 780. The error code at step780 may indicate that the thread characteristics of the scanned billdoes not match any of the stored master thread information associatedwith genuine bills.

If at step 766 the master magnetic information for the denominationindicated in step 762 does not match the detected magnetic informationfor the bill under test, the bill is denominated again (at step 782) butthis time using magnetic information. If the detected magneticinformation sufficiently matches (step 784) any of the stored mastermagnetic information, an appropriate error code is issued at step 786.Because the bill failed the test at step 766, if the scanned magneticinformation matches any of the stored master magnetic information, thematching master magnetic information will be associated with adenomination other than the denomination determined optically at step762. Accordingly, at step 786, the magnetically determined denominationdiffers from the optically determined denomination and an appropriateerror code may be generated such as a no call code indicating that theoptical and magnetic tests resulted in different denominationdeterminations thus preventing the system from calling the denominationof the bill under test. If the detected magnetic information does notmatch (step 784) any of the stored master magnetic information, anappropriate suspect code is issued at step 788. The error code at step788 may indicate that the scanned bill does not match magnetically anyof the stored master magnetic information associated with genuine bills.

According to the flowchart of FIG. 46, at step 782, a bill is opticallydenominated, for example, according to the methods described above inconnection with FIG. 25. Provided the denomination of the bill isdetermined at step 782, the bill is then authenticated based on threadlocation and/or color at step 784. The authentication step 784 may beperformed, for example, according to the methods described in connectionwith in FIGS. 26-28. At step 784, however, the detected threadinformation is only compared to master thread information associatedwith the denomination determined in step 782. If the master threadinformation for the denomination indicated in step 782 matches (step786) the detected thread information for the bill under test, the billis then magnetically authenticated at step 788. The magneticauthentication step 788 may be performed, for example, according to themethods described in connection with in FIG. 29. At step 788, however,the detected magnetic information is only compared to master magneticinformation associated with the denomination determined in step 782. Ifthe master magnetic information for the denomination indicated in step782 matches (step 790) the detected magnetic information for the billunder test, the bill is indicated (at step 791) to have the denominationas determined at step 782. Otherwise, the bill is denominated again (atstep 792) but this time using magnetic information. If the detectedmagnetic information sufficiently matches (step 793) any of the storedmaster magnetic information, an appropriate error code is issued at step794. Because the bill failed the test at step 790, if the scannedmagnetic information matches any of the stored master magneticinformation, the matching master magnetic information will be associatedwith a denomination other than the denomination determined optically atstep 782. Accordingly, at step 794, the magnetically determineddenomination differs from the optically determined denomination and anappropriate error code may be generated such as a no call codeindicating that the optical and magnetic tests resulted in differentdenomination determinations thus preventing the system from calling thedenomination of the bill under test. If the detected magneticinformation does not match (step 793) any of the stored master magneticinformation, an appropriate suspect code is issued at step 795. Theerror code at step 795 may indicate that the scanned bill does not matchmagnetically any of the stored master magnetic information associatedwith genuine bills.

If at step 786 the master thread information for the denominationindicated in step 782 does not match the detected thread information forthe bill under test, the bill is denominated again (at step 796) butthis time using thread information. If the detected thread informationmatches (step 797) any of the stored master thread information, anappropriate error code is issued at step 798. Because the bill failedthe test at step 786, if the thread-based information matches any of thestored master thread information, the matching master thread informationwill be associated with a denomination other than the denominationdetermined at step 782. Accordingly, at step 798, the thread-baseddetermined denomination differs from the optically determineddenomination and an appropriate error code may be generated such as a nocall code indicating that the thread-based and optical tests resulted indifferent denomination determinations thus preventing the system fromcalling the denomination of the bill under test. If the detected threadinformation does not match (step 797) any of the stored master threadinformation, an appropriate suspect code is issued at step 799. Theerror code at step 799 may indicate that the thread characteristics ofthe scanned bill does not match any of the stored master threadinformation associated with genuine bills.

FIG. 47 illustrates a method where for a bill to be accepted it is firstdenominated utilizing first characteristic information, thenauthenticated using second characteristic information, then denominatedusing the second characteristic information, and finally authenticatedusing third characteristic information. According to the flowchart ofFIG. 47, at step 800, a bill is magnetically denominated, for example,according to the methods described above in connection with FIG. 29.Provided the denomination of the bill is magnetically determined at step800, the bill is then optically authenticated at step 802. The opticalauthentication step 802 may be performed, for example, according to themethods described in connection with in FIG. 25. At step 802, however,the detected optical information is only compared to master opticalinformation associated with the denomination determined in step 800. Ifthe master optical information for the denomination indicated in step800 does not sufficiently match (step 804) the detected opticalinformation for the bill under test, an appropriate suspect code isissued at step 806. Otherwise, the bill is denominated again (at step808) but this time using optical information. If the opticallydetermined denomination does not match (step 810) the magneticallydetermined denomination, an appropriate error code is issued at step812. If the optically determined denomination does match (step 810) themagnetically determined denomination, the bill is then authenticatedbased on thread location and/or color at step 814. The authenticationstep 814 may be performed, for example, according to the methodsdescribed in connection with in FIGS. 26-28. At step 814, however, thedetected thread information is only compared to master threadinformation associated with the denomination determined in step 800. Ifthe master thread information for the denomination indicated in step 800matches (step 816) the detected thread information for the bill undertest, the bill is accepted and indicated (at step 818) to have thedenomination as determined at step 800. Otherwise, the bill isdenominated again (at step 820) but this time using thread information.If the detected thread information matches (step 822) any of the storedmaster thread information, an appropriate error code is issued at step824. Because the bill failed the test at step 816, if the thread-basedinformation matches any of the stored master thread information, thematching master thread information will be associated with adenomination other than the denomination determined at step 800.Accordingly, at step 824, the thread-based determined denominationdiffers from the magnetically determined denomination and an appropriateerror code may be generated such as a no call code indicating that thethread-based and magnetic tests resulted in different denominationdeterminations thus preventing the system from calling the denominationof the bill under test. If the detected thread information does notmatch (step 822) any of the stored master thread information, anappropriate suspect code is issued at step 826. The error code at step826 may indicate that the thread characteristics of the scanned billdoes not match any of the stored master thread information associatedwith genuine bills.

FIGS. 45-47 provide examples of combinations of characteristicinformation employed as first, second, and third characteristicinformation. Alternatively, the methods of FIGS. 45-47 may be performedwith other combinations of characteristic information wherein the first,second, and third characteristic information comprise a variety ofcharacteristic information as described above such as magnetic, optical,color, and thread based information.

In general, with respect to the methods described above in connectionwith FIGS. 25-47, the decision whether to authenticate a bill using oneor more tests and/or to denominate a bill two or more times may be basedon the value of the note as determined during the initial denominatingstep. For example, for a bill initially determined to be a $1 or $2 billusing a first denominating method, it may be desirable to immediatelyaccept the bill or perform one authentication test such as illustratedin FIGS. 25-33. For bills initially determined to be of some immediatevalue such as $5 and $10 bills, it may be desirable to perform a seconddenominating step and/or an authenticating step before accepting thebill such as in FIGS. 34-36 and 38, and 43-44. For bills initiallydetermined to be of a high value such as $20, $50, and $100 bills, itmay be desirable to perform two, three, or more denominating and/orauthenticating steps such as in FIGS. 37 and 45-47.

Likewise, it may be desirable to perform additional denominating and/orauthenticating steps in unattended currency handling machines such asunattended redemption machines. Additional screening steps may bedesirable with these machines that accept money directly from customerssuch as bank customers or casino patrons for credit to their accounts ordenomination exchanges as opposed to machines employed in environmentswhere an employee such as a bank teller or casino employee receivesmoney from customers and then the employee processes the bills with theaid of the currency machine.

The above described embodiments of sensors and methods may be employedin currency discriminators such as, for example, those described abovein connection with FIGS. 4a, 6-12, 15 or the discriminator described inU.S. Pat. No. 5,295,196 incorporated herein by reference.

The issuance of an error code such as a no call code or a suspect codemay be used to suspend processing of a stack of bills, for example, asdescribed in U.S. Pat. No. 5,295,196 incorporated herein by reference.These codes may cause the operation of a single or multiple outputpocket discriminator to be suspended such that the bill triggering oneof these codes is the last bill delivered to an output pocket before theoperation of the system is suspended. Alternatively, a random bill maytrigger these codes, for example the second-to-last bill. Accordingly,the triggering bill may be easily examined by the operator of the systemso that appropriate action may be taken based on the operator'sevaluation of the triggering bill. Alternatively, in a multiple outputpocket system such as a two output pocket system, the issuance of one ofthese error codes may cause triggering bills to be diverted to adifferent output pocket such as a reject pocket. Alternatively, billsthat result in a no call code may be diverted to one output pocket andthose that result in a suspect code may be diverted to a differentpocket. Accepted bills may be routed to one or more other outputpockets.

The operation of selection elements will now be described in more detailin conjunction with FIG. 48a which is a front view of a control panel1061 of one embodiment of the present invention. The control panel 1061comprises a keypad 1062 and a display section 1063. The keypad 1062comprises a plurality of keys including seven denomination selectionelements 1064 a-1064 g, each associated with one of seven U.S. currencydenominations, i.e. $1, $2, $5, $10, $20, $50, and $100. Alternatively,the keys may be for 2, 5, 10, 20 and 50 ⊚ notes or any combination offoreign currency. For document processing systems, the denominationselection elements may be labeled according to the currency system whicha system is designed to handle and accordingly, there may be more orless than seven denomination selection elements. The $1 denominationselection key 64 a also serves as a mode selection key. It should benoted that the denomination selection elements can be used to enter notonly the value of currency, but all types of documents including checks.The keypad 1062 also comprises a “Continuation” selection element 1065.Various information such as instructions, mode selection information,authentication and discrimination information, individual denominationcounter values, and total batch counter value are communicated to theoperator via an LCD 1066 in the display section 1063. The full imageprocessing unit and the discrimination and authentication unit accordingto one embodiment of the present invention have a number of operatingmodes including a mixed mode, a stranger mode, a sort mode, a face mode,and a forward/reverse orientation mode.

FIG. 48b illustrates an alternate embodiment of the control panel 1061.A set of numeric keys with a decimal point collectively labeled 1064 his engaged by the user to enter numeric data from all types ofdocuments. FIG. 48c illustrates a control panel 1061 with both numerickeys and decimal point 1064 h and denomination keys 1064 a-1064 f Theuser has the choice of entering the data by the denomination keys 1064a-1064 f or the numeric keys. The remaining elements of the controlpanels in FIGS. 48b and 48 c function as described above.

The operation of a document processing system having the denominationselection elements 1064 a-1064 g and the continuation element 1065 willnow be discussed in connection with several operating modes.

(A) Mixed Mode

Mixed mode is designed to accept a stack of bills of mixed denomination,total the aggregate value of all the bills in the stack and display theaggregate value in the display 1063. By “stack” it is meant to not onlyinclude a single stack of bills, but multiple stacks as well.Information regarding the number of bills of each individualdenomination in a stack may also be stored in denomination counters.When an otherwise acceptable bill remains unidentified after passingthrough the system, operation of the system may be resumed and thecorresponding denomination counter and/or the aggregate value countermay be appropriately incremented by selecting the denomination selectionkey 1064 a-1064 g associated with the denomination of the unidentifiedbill. For example, if the system stops operation with an otherwiseacceptable $5 bill being the last bill deposited in the outputreceptacle, the operator may simply select key 64 b. When key 64 b isdepressed, the operation of the system is resumed and the $5denomination counter is incremented and/or the aggregate value counteris incremented by $5. Furthermore, the flagged bill may be routed fromthe inspection station to an appropriate output receptacle. Otherwise,if the operator determines the flagged bill is unacceptable, the billmay be removed from the output receptacle or the inspection station orthe flagged bill may be routed to the reject receptacle. Thecontinuation key 1065 is depressed after the unacceptable bill isremoved, and the system resumes operation without affecting the totalvalue counter and/or the individual denomination counters.

(B) Stranger Mode

Stranger mode is designed to accommodate a stack of bills all having thesame denomination, such as a stack of $10 bills. In such a mode, when astack of bills is processed by the system the denomination of the firstbill in the stack is determined and subsequent bills are flagged if theyare not of the same denomination. Alternatively, the system may bedesigned to permit the operator to designate the denomination againstwhich bills will be evaluated with those of a different denominationbeing flagged. Assuming the first bill in a stack determines therelevant denomination and assuming the first bill is a $10 bill, thenprovided all the bills in the stack are $10 bills, the display 1063 willindicate the aggregate value of the bills in the stack and/or the numberof $10 bills in the stack. However, if a bill having a denominationother than $10 is included in the stack, the system will stop operatingwith the non-$10 bill or “stranger bill” being the last bill depositedin the output receptacle in the case of the discriminator system or theinspection station. The stranger bill may then be removed from theoutput receptacle and the system is started again either automaticallyor by depression of the “Continuation” key 1065 depending on the set upof the system. An unidentified but otherwise acceptable $10 bill may behandled in a manner similar to that described above in connection withthe mixed mode, e.g., by depressing the $10 denomination selectionelement 1064 c, or alternatively, the unidentified but otherwiseacceptable $10 bill may be removed from the output receptacle and placedinto the input hopper to be re-scanned. Upon the completion ofprocessing the entire stack, the display 1063 will indicate theaggregate value of the $10 bills in the stack and/or the number of $10bills in the stack. All bills having a denomination other than $10 willhave been set aside and will not be included in the totals.Alternatively, these stranger bills can be included in the totals viaoperator selection choices. For example, if a $5 stranger bill isdetected and flagged in a stack of $10 bills, the operator may beprompted via the display as to whether the $5 bill should beincorporated into the running totals. If the operator respondspositively, the $5 bill is incorporated into appropriate running totals,otherwise it is not. Alternatively, when the system stops on a strangerbill, such as a $5, the operator may depress the denomination selectionelement associated with that denomination to cause the value of thestranger bill to be incorporated into the totals. Likewise for othertypes of flagged bills such as no calls. Alternatively, a set-upselection may be chosen whereby all stranger bills are automaticallyincorporated into appropriate running totals.

(C) Sort Mode

According to one embodiment, the sort mode is designed to accommodate astack of bills wherein the bills are separated by denomination. Forexample, all the $1 bills may be placed at the beginning of the stack,followed by all the $5 bills, followed by all the $10 bills, etc.Alternatively, the sort mode may be used in conjunction with a stack ofbills wherein the bills are mixed by denomination. The operation of thesort mode is similar to that of the stranger mode except that afterstopping upon the detection of a different denomination bill, the systemis designed to resume operation upon removal of all bills from theoutput receptacle. Returning to the above example, assuming the firstbill in a stack determines the relevant denomination and assuming thefirst bill is a $1 bill, then the system processes the bills in thestack until the first non-$1 bill is detected, which in this example isthe first $5 bill. At that point, the system will stop operating withthe first $5 being the last bill deposited in the output receptacle. Thedisplay 1063 may be designed to indicate the aggregate value of thepreceding $1 bills processed and/or the number of preceding $1 bills.The scanned $1 bills and the first $5 bill are removed from the outputreceptacle and placed in separate $1 and $5 bill stacks. The system willstart again automatically and subsequent bills will be assessed relativeto being $5 bills. The system continues processing bills until the first$10 bill is encountered. The above procedure is repeated and the systemresumes operation until encountering the first bill which is not a $10bill, and so on. Upon the completion of processing the entire stack, thedisplay 1063 will indicate the aggregate value of all the bills in thestack and/or the number of bills of each denomination in the stack. Thismode permits the operator to separate a stack of bills having multipledenominations into separate stacks according to denomination.

(D) Face Mode

Face mode is designed to accommodate a stack of bills all faced in thesame direction, e.g., all placed in the input receptacle face up (thatis the portrait or black side up for U.S. bills) and to detect any billsfacing the opposite direction. In such a mode, when a stack of bills isprocessed by the system, the face orientation of the first bill in thestack is determined and subsequent bills are flagged if they do not havethe same face orientation. Alternatively, the system may be designed topermit designation of the face orientation to which bills will beevaluated with those having a different face orientation being flagged.Assuming the first bill in a stack determines the relevant faceorientation and assuming the first bill is face up, then provided allthe bills in the stack are face up, the display 1063 will indicate theaggregate value of the bills in the stack and/or the number of bills ofeach denomination in the stack. However, if a bill faced in the oppositedirection (i.e., face down in this example) is included in the stack,the system will stop operating with the reverse-faced bill being thelast bill deposited in the output receptacle. The reverse-faced billthen may be removed from the output receptacle. In automatic re-startembodiments, the removal of the reverse-faced bill causes the system tocontinue operating. The removed bill may then be placed into the inputreceptacle with the proper face orientation. Alternatively, innon-automatic re-start embodiments, the reverse-faced bill may be eitherplaced into the input receptacle with the proper face orientation andthe continuation key 1065 depressed, or placed back into the outputreceptacle with the proper face orientation. Depending on the set up ofthe system when a bill is placed back into the output receptacle withthe proper face orientation, the denomination selection key associatedwith the reverse-faced bill may be selected, whereby the associateddenomination counter and/or aggregate value counter are appropriatelyincremented and the system resumes operation. Alternatively, inembodiments wherein the system is capable of determining denominationregardless of face orientation, the continuation key 1065 or a third keymay be depressed whereby the system resumes operation and theappropriate denomination counter and/or total value counter isincremented in accordance with the denomination identified by thediscriminating system. In systems that require a specific faceorientation, any reverse-faced bills will be unidentified bills. Insystems that can accept a bill regardless of face orientation,reverse-faced bills may be properly identified. The later type of systemmay have a discrimination and authentication system with a scanhead oneach side of the transport path. Examples of such dual-sided systems aredisclosed above. The ability to detect and correct for reverse-facedbills is important as the Federal Reserve requires currency it receivesto be faced in the same direction.

In a multi-output receptacle system, the face mode may be used to routeall bills facing upward to one output receptacle and all bills facingdownward to another output receptacle. In single-sided discriminators,reverse-faced bills may be routed to an inspection station for manualturnover by the operator and the unidentified reverse-faced bills maythen be passed by the system again. In dual-sided systems, identifiedreverse-faced bills may be routed directly to an appropriate outputreceptacle. For example, in dual-sided discriminators bills may besorted both by face orientation and by denomination. e.g., face up $1bills into pocket #1, face down $1 bills into pocket #2, face up $5bills into pocket #3, and so on or simply by denomination, regardless offace orientation, e.g., all $1 bills into pocket #1 regardless of faceorientation, all $2 bills into pocket #2, etc.

(E) Forward/Reverse Orientation Mode

Forward/Reverse Orientation mode (“Orientation” mode) is designed toaccommodate a stack of bills all oriented in a predetermined forward orreverse orientation direction. For example in a system that feeds billsalong their narrow dimension, the forward direction may be defined asthe fed direction whereby the top edge of a bill is fed first andconversely for the reverse direction. In a system that feeds bills alongtheir long dimension, the forward direction may be defined as the feddirection whereby the left edge of a bill is fed first and converselyfor the reverse direction. In such a mode, when a stack of bills isprocessed by the system, the forward/reverse orientation of the firstbill in the stack is determined and subsequent bills are flagged if theydo not have the same forward/reverse orientation. Alternatively, thesystem may be designed to permit the operator to designate theforward/reverse orientation against which bills will be evaluated withthose having a different forward/reverse orientation being flagged.Assuming the first bill in a stack determines the relevantforward/reverse orientation and assuming the first bill is fed in theforward direction, then provided all the bills in the stack are also fedin the forward direction, the display 63 will indicate the aggregatevalue of the bills in the stack and/or the number of bills of eachdenomination in the stack. However, if a bill having the oppositeforward/reverse orientation is included in the stack, the system willstop operating with the opposite forward/reverse oriented bill being thelast bill deposited in the output receptacle. The oppositeforward/reverse oriented bill then may be removed from the outputreceptacle. In automatic re-start embodiments, the removal of theopposite forward/reverse oriented bill causes the system to continueoperating. The removed bill may then be placed into the input receptaclewith the proper face orientation. Alternatively, in non-automaticre-start embodiments, the opposite forward/reverse oriented bill may beeither placed into the input receptacle with the proper forward/reverseorientation and the continuation key 65 depressed, or placed back intothe output receptacle with the proper forward/reverse orientation.Depending on the set up of the system, when a bill is placed back intothe output receptacle with the proper forward/reverse orientation, thedenomination selection key associated with the opposite forward/reverseoriented bill may be selected, whereby the associated denominationcounter and/or aggregate value counter are appropriately incremented andthe system resumes operation. Alternatively, in embodiments wherein thesystem is capable of determining denomination regardless offorward/reverse orientation, the continuation key 1065 or a the thirdkey may be depressed whereby the system resumes operation and theappropriate denomination counter and/or total value counter isincremented in accordance with the denomination identified by thesystem. In single-direction systems, any reverse-oriented bills will beunidentified bills. In dual-direction units, reverse-oriented bills maybe properly identified by the discriminating unit. An example of adual-direction system is described in U.S. Pat. No. 5,295,196. Theability to detect and correct for reverse-oriented bills is important asthe Federal Reserve may soon require currency it receives to be orientedin the same forward/reverse direction.

In a multi-output receptacle system, the orientation mode may be used toroute all bills oriented in the forward direction to one outputreceptacle and all bills oriented in the reverse direction to anotheroutput receptacle. In single-direction discriminators, reverse-orientedbills may be routed to an inspection station for manual turnover by theoperator and the unidentified reverse-oriented bills may then be passedby the system again. In systems capable of identifying bills fed in bothforward and reverse directions (“dual-direction systems”), identifiedreverse-oriented bills may be routed directly to an appropriate outputreceptacle. For example, in dual-direction systems bills may be sortedboth by forward/reverse orientation and by denomination, e.g., forward$1 bills into pocket #1, reverse $1 bills into pocket #2, forward $5bills into pocket #3, and so on or simply by denomination, regardless offorward/reverse orientation, e.g., all $1 bills into pocket #1regardless of forward/reverse orientation, all $2 bills into pocket #2,etc.

(F) Suspect Mode

In addition to the above modes, a suspect mode may be activated inconnection with these modes whereby one or more authentication tests maybe performed on the bills in a stack. When a bill fails anauthentication test, the system will stop with the failing or suspectbill being the last bill transported to the output receptacle. Thesuspect bill then may be removed from the output receptacle and setaside.

(G) Other Modes

A proof of deposit mode may be activated when a user presses a dedicatedkey on the machine. This mode enables the system to process checks, loanpayment coupons, and other proof of deposit media. Another key may bepressed to activate bank source mode. When the machine is in this mode,the output documents are separated into documents from one source anddocuments from all other sources. For example, checks may be separatedinto checks issued from the bank which owns the machine and checksissued by all other financial institutions. Such separation may beaccomplished by using two bins or one bin whereby the machine stops whenan “outside” check (i.e., a check from a non-owner financialinstitution) is detected. Finally, the user may press a key to have themachine enter stored image mode. When operating in this mode, the systemholds deposit images at the machine which is later polled for datapickup by the central accounting system. Such a mode eases datacongestion between the system and the central accounting system.

Likewise, one or more of the above described modes may be activated atthe same time. For example, the face mode and the forward/reverseorientation mode may be activated at the same time. In such a case,bills that are either reverse-faced or opposite forward/reverse orientedwill be flagged.

According to one embodiment, when a bill is flagged, for example, bystopping the transport motor with the flagged bill being the last billdeposited in the output receptacle, the discrimination andauthentication unit indicates to the operator why the bill was flagged.This indication may be accomplished by, for example, lighting anappropriate light, generating an appropriate sound, and/or displaying anappropriate message in the display section 1063 (FIG. 48). Suchindication might include, for example, “no call”, “stranger”, “failedmagnetic test”, “failed UV test”, “no security thread”, etc.

Means for entering the value of no call bills or other documents werediscussed above in connection with FIG. 48 and the operating modesdiscussed above. Now several additional means will be discussed inconnection with FIGS. 49-53. FIG. 49a is a front view of a control panel2302 similar to that of FIG. 48. The control panel 2302 comprises adisplay area 2304, several denomination selection elements 2306 a-g inthe form of keys, left and right scroll keys 2308 a-b, an acceptselection element 2310, and a continuation selection element 2312. Eachdenomination selection element 2306 a-g has a prompting means associatedtherewith. In FIG. 49a, the prompting means are in the form of smalllights or lamps 2314 a-g such as LEDs. In FIG. 49a, the light 2314 dassociated with the $10 denomination key 2306 d is illuminated so as toprompt the operator that a denomination of $10 is being suggested.Alternatively, instead of the lamps 2314 a-g being separate from thedenomination keys 2306 a-g, the denomination keys could be in the formof illimitable keys whereby one of the keys 2306 a-g would light up tosuggest its corresponding denomination to the operator. In place of, orin addition to, the illimitable lights 23 14 a-g or keys, the displayarea 2304 may contain a message to prompt or suggest a denomination tothe operator. In FIG. 49a, the display area 2304 contains the message“$10?” to suggest the denomination of $10. In the embodiment of FIG. 48,the display area 1063 may be used to suggest a denomination to theoperator without the need of illimitable lights and keys. The value ofany document can also be entered via the keyboard.

FIG. 49b illustrates a control panel similar to that of FIG. 49a exceptthat the denomination keys have been replaced by numeric keys and adecimal point which are collectively referred to as 2314 h. Additionallights 23 14 i-k are used by the system to suggest values to be enteredby the user. The remainder of the panel functions as described above.This embodiment is particularly useful in processing financialinstitution documents although it can be used for currency as well.

The control panel 2402 of FIG. 50a is similar to the control panel 2302of FIG. 49a; however, the denomination selection elements 2406 a-g,scroll keys 2408 a-b, accept key 2410, and continuation key 2412 aredisplayed keys in a touch-screen environment. To select any given key,the operator touches the screen in the area of the key to be selected.The operation of a touch screen is described in more detail inconnection with FIG. 55. The system may contain prompting means tosuggest a denomination to the operator. For example, an appropriatemessage may be displayed in a display area 2404. Alternatively, oradditionally, the prompting means may include means for highlighting oneof the denomination selection elements 2406 a-g. For example, theappearance of one of the denomination selection elements may be alteredsuch as by making it lighter or darker than the remaining denominationselection elements or reversing the video display (e.g., making lightportions dark and making the dark portions light or swapping thebackground and foreground colors). Alternatively, a designateddenomination selection element may be highlighted by surrounding it witha box, such as box 2414 surrounding the $10 key 2406 d.

FIG. 50b illustrates a control panel similar to that of FIG. 50a exceptthat the denomination keys have been replaced by numeric keys and adecimal point which are collectively referred to as 2313 h. Theremainder of the panel functions as described above. This embodiment isparticularly useful in processing financial institution documentsalthough it can be used for currency as well.

Another embodiment of a control panel 2502 is depicted in FIG. 51a. Thecontrol panel 2502 has several denomination indicating elements 2506 a-gin the form of menu list 2505, scroll keys 2508 a-b, an accept selectionelement 2510, and a continuation selection element 2512. The variousselection elements may be, for example, physical keys or displayed keysin a touch screen environment. For example, the menu list 2505 may bedisplayed in a non-touch screen activated display area while the scrollkeys 2508 a-b, accept key 2510, and continuation key 2512 may bephysical keys or displayed touch screen keys. In such an environment auser may accept a denominational selection by pressing the accept key2510 when the desired denomination indicating element is highlighted andmay use the scroll keys 2508 a-b to vary the denomination indicatingelement that is highlighted. Alternatively, the denomination indicatingelements 2506 a-g may themselves be selection elements such as by beingdisplayed touch screen active keys. In such an embodiment a givendenomination element may be made to be highlighted and/or selected bytouching the screen in the area of one of the denomination selectionelements 2506 a-g. The touching of the screen in the area of one of thedenomination selection elements may simply cause the associateddenomination selection element to become highlighted requiring thetouching and/or pressing of the accept key 2510 or alternatively mayconstitute acceptance of the associated denomination selection elementwithout requiring the separate selection of the accept key 2510. Thediscrimination and authentication unit may contain prompting means tosuggest a denomination to the operator. For example, an appropriatemessage may be displayed in a display area 2504. Alternatively, oradditionally, the prompting means may include means for highlighting oneof the denomination indicating elements 2506 a-g. For example, theappearance of one of the denomination indicating elements may be alteredsuch as by making it lighter or darker than the remaining denominationindicating elements or by reversing the video display (e.g., makinglight portions dark and making the dark portions light or swapping thebackground and foreground colors). In FIG. 51a, the hash marks are usedto symbolize the alternating of the display of the $10 denominationindicating element 2506 d relative to the other denomination indicatingelements such as by using a reverse video display.

FIG. 51b illustrates a control panel similar to that of FIG. 51a exceptthat the denomination selection elements have been replaced by numericand a decimal selection elements which are collectively referred to as2506 h. The remainder of the panel functions as described above. Thisembodiment is particularly useful in processing financial institutiondocuments although it can be used for currency as well.

Control panel 2602 of FIG. 52 is similar to control panel 2502 of FIG.51; however, the control panel 2602 does not have a separate displayarea. Additionally, the order of the denomination indicating elements2606 a-g of menu list 2605 is varied relative to those of menu list2505. The order of the denomination selection element may beuser-defined (i.e., the operator may preset the order in which thedenominations should be listed) or may be determined by thediscrimination and authentication unit and be, for example, based on thehistorical occurrence of no calls of each denomination, based on thedenomination of the most recently detected no call, based on calculatedcorrelation values for a given no call bill, or perhaps based on randomselection. Such criteria will be described in more detail below.

The control panel 2702 of FIGS. 53a and 53 b comprises a display area2704, an accept key 2710, a next or other denomination key 2711, and acontinuation key 2712. Alternatively, the accept key may be designated a“YES” key while the other denomination key may be designated a “NO” key.These keys may be physical keys or displayed keys. The system prompts orsuggest a denomination by displaying an appropriate message in thedisplay area 2704. If the operator wishes to accept this denominationsuggestion, the accept key 2710 may be selected. If other the operatorwishes to select a different denomination, the other denomination key2711 may be selected. If in the example given in FIG. 53a the operatorwishes to select a denomination other than the $5 prompted in thedisplay area 2704, the other denomination key 2711 may be selected whichresults in prompting of a different denomination, e.g., $2 as shown inFIG. 53b. The “OTHER DENOM” key 2711 may be repeatedly selected toscroll through the different denominations.

The control panel 2802 of FIG. 54 is similar to that of FIGS. 53a-b andadditionally comprises scroll keys 2808 a-b. These scroll keys 2808 a-bmay be provided in addition to or in place of the other denomination key2811. The order in which denominations are suggested to an operator, forexample, in FIGS. 53 and 54, may be based on a variety of criteria aswill be discussed below such as user-defined criteria or order,historical information, previous bill denomination, correlation values,or previous no call information.

Now several embodiments of the operation of the control panels such asthose of FIGS. 48 and 49-54 will be discussed. These can be employed inconjunction with a variety of discriminators and scanners. Inparticular, several methods for reconciling the value of no call billswill be discussed in connection with these control panels. As discussedabove, for example, in connection with the several previously describedoperating modes, when a system encounters a no call bill, that is, whena system is unable to determine or call the denomination of a bill, anycounters keeping track of the number or value of each denomination ofbills or of the total value of the bills processed will not include theno call bill. Traditionally, any no calls bills had to be set aside andmanually counted by hand with the operator being required to add theirvalues to the totals provided by the discrimination and authenticationunit or the full-imaging unit. As discussed above, this can lead toerrors and reduced efficiency. To counter this problem, according to anembodiment of the present invention, means are provided forincorporating the value of no call bills. In single pocket systems,reconciliation may be accomplished on-the-fly with the system suspendingoperation when each no call is encountered, prompting the operator toenter the value of the no call, and then resuming operation. Inmulti-output pocket systems, no call bills may be reconciled eitheron-the-fly or after the completion of processing all the bills placed inthe input hopper or after completion of processing some other designatedbatch of bills. Under the first approach, the operation of the system issuspended when each no call bill is detected with or without the no callbill being routed to a special location. The operator is then promptedto enter the value of the no call where upon the system resumesoperation. Based on the value indicated by the operator, appropriatecounters are augmented. Under the second approach, any no call bills arerouted to a special location while the discrimination and authenticationunit or the full image processing unit continue processing subsequentbills. When all the bills have been processed, the operator is promptedto reconcile the values of any intervening no call bills. For example,assume a stack of fifty bills is placed in the input hopper andprocessed with four no calls being routed to a separate outputreceptacle from the receptacle or receptacles into which the bills whosedenominations have been determined. After all fifty bills have beenprocessed, the operation of the transport mechanism is halted and theoperator is prompted to reconcile the value of the four no call bills.The methods for reconciling these four no calls will be discussed belowafter describing several denomination indicating and/or prompting meansand methods. Alternatively, instead of waiting until all the bills inthe stack have been processed, the system may prompt the operator toreconcile the value of any no call bills while the remaining bills arestill being processed. When the operator indicates the denominations ofthe no call bills, appropriate counters are augmented to reflect thevalue of the no call bills.

Several embodiments of means for permitting the operator to indicate thevalue of a flagged bill or document such as a no call and/or forprompting the operator as to the value of a flagged bill such as a nocall will no w be discussed. A first method was discussed above inconnection with several operating modes and in connection with FIG. 48.According to one embodiment, the control panel of FIG. 48 comprisesdenomination indicating means in the form of the denomination selectionelements 2064 a-g for permitting the operator to indicate thedenomination of a bill but does not additionally comprise means forprompting the operator as to the denomination of a particular bill.Under this method, the operator examines a no call bill. If the bill isacceptable, the operator selects the denomination selection elementassociated with the denomination of the no call bill and the appropriatecounters are augmented to reflect the value of the no call bill. Forexample, if the operator determines a no call bill is an acceptable $10bill, the operator may press the $10 selection element 2064 c of FIG.48. If the operation of the system had been suspended, the selection ofa denomination selection causes the operation of the system to resume.In a on-the-fly reconciliating machine (i.e., one that suspendsoperation upon detection of each no call bill), if the operatordetermines that a particular no call bill is unacceptable, acontinuation selection element may be selected to cause the system toresume operation without negatively affecting the status of anycounters. Under this approach, the denomination selection elementsprovide the operator with means for indicating the value of a no callbill. In FIGS. 49-54, additional examples of means for indicating thevalue of no call bills are provided. For example, in FIGS. 49-52,according to one embodiment, a denomination may be indicated in asimilar manner by pressing one of the denomination selection elements.Alternatively, or additionally, a denomination may be indicated byselecting one of the denomination selection elements and selecting anaccept key. Another example of a method of indicating a particulardenomination selection element would be by utilizing one or more scrollkeys. The selection of a denomination selection element may be indicatedby, for example, the lights 2314 of FIG. 51, or by highlighting aparticular selection element as in FIGS. 50-52. Alternatively adisplayed message, as in FIGS. 49-51, 53, and 54, may be used toindicate which denomination is currently selected. The scroll keys couldbe used to alter which denomination is presently selected, for example,by altering which light 2314 is illuminated, which selection element ishighlighted, or which denomination appears in the displayed message.Selection of an accept key while a particular denomination is selectedmay be used to indicate the selected denomination to the discriminationand authentication unit or the full image processing unit.

In addition to means for permitting the operator to indicate thedenomination of one or more no calls, a document processing system maybe provided with one or more means of prompting the operator as to thedenomination of a no call bill. These means can be the means used toindicate which denomination is currently selected, e.g., the lights 2314of FIG. 49, the highlighting of FIGS. 50-52, and/or the displayedmessage of FIGS. 49-51, 53, and 54. Several methods that may be employedin prompting the operator to enter the value of one or more no callbills will now be discussed.

A system containing means for prompting an operator as to the value of ano call bill or document may base its selection of the denomination tobe prompted to the operator on a variety of criteria. According to oneembodiment, default denomination or sequence of denominations may beemployed to prompt a denomination to an operator. For example, thesystem may begin by prompting the lowest denomination, e.g., $1.Alternatively, the operator may begin by prompting the operator with thefirst denomination in a pre-defined sequence or on a menu list. Theorder of the denominations in the sequence or on the menu list may be adefault order, e.g., increasing or decreasing denominational order,user-defined order, manufacturer-defined order.

According to another embodiment, a denomination to be prompted to theoperator is determined on a random basis. The system simply randomly orpseudo-randomly chooses one of a plurality of denominations and suggeststhis denomination to the operator. The denomination prompted to anoperator may remain the same for all no call bills or alternatively, anew randomly selected denomination may be chosen for each no callencountered. If the operator agrees that a given no call bill is of thedenomination suggested by the prompting means and finds the particularno call bill to be acceptable, the operator may simply choose the acceptelement or the corresponding denomination selection element depending onthe embodiment of the control panel employed. If the operator finds aparticular bill to be acceptable but does not have the suggesteddenomination, the operator may alter the denomination that is selectedby, for example, altering the displayed suggested denomination by usingthe scroll keys, scrolling among the plurality of denomination selectionand/or indicating elements, or directly selecting the appropriatedenomination by pressing or touching the appropriate denominationselection element. If the operator finds that a no call bill is notacceptable, the operator may simply select a continuation key.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of the denomination of the last billthat was identified by the system. For example, suppose the tenth billin a stack was determined by the system to be a $10, the eleventh billwas a no call and indicated by the operator to be a $5 bill, and thetwelfth was a no call bill. According to this embodiment, the systemwould suggest to the operator that the twelfth bill is a $10 bill. Theoperator may accept this suggestion or alter the suggested denominationas described above.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of the denomination of the last nocall bill as indicated by the operator. For example, suppose the tenthbill was a no call and indicated by the operator to be a $5 bill, theeleventh bill in a stack was determined by the system to be a $10, andthe twelfth was a no call bill. According to this embodiment, the systemwould suggest to the operator that the twelfth bill is a $5 bill. Theoperator may accept this suggestion or alter the suggested denominationas described above.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of the denomination of theimmediately preceding bill, regardless of whether the denomination ofthat bill was determined by the system or was indicated by the operator.For example, suppose the tenth bill in a stack was determined by thesystem to be a $10, the eleventh bill was a no call and indicated by theoperator to be a $5 bill, and the twelfth was also a no call bill.According to this embodiment, the system would suggest to the operatorthat the twelfth bill is a $5 bill. The operator may accept thissuggestion or alter the suggested denomination as described above.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of historical information concerningno call bills such as statistical information regarding previous no callbills. For example, suppose that for a given system 180 no calls hadbeen encountered since the system was placed in service. According tothis embodiment, information regarding these no calls is stored inmemory. Assume that of these 180 no call bills, 100 were indicated bythe operator to be $5s, 50 were $10s, and the remaining 30 were $20s.According to this embodiment, the system would suggest to the operatorthat a no call bill was a $5. The operator may accept this suggestion oralter the suggested denomination as described above. Variations on thedata which constitute the historical basis may be made. For example, thehistorical basis according to this embodiment may be all no callsencountered since a given machine was place in service as in the aboveexample, the last predetermined number of no calls detected, e.g., thelast 100 no calls detected, or the last predetermined number of billsprocessed, e.g., the no calls encountered in the last 1000 billsprocessed. Alternatively the historical basis may be set by themanufacturer based on historical data retrieved from a number ofsystems.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of a comparison of informationretrieved from a given no call bill and master information associatedwith genuine bills. For example, in some systems, the denomination of abill is determined by scanning the bill, generating a scanned patternfrom information retrieved via the scanning step, and comparing thescanned pattern with one or more master patterns associated with one ormore genuine bills associated with one or more denominations. If thescanned pattern sufficiently matches one of the master patterns, thedenomination of the bill is called or determined to be the denominationassociated with the best matching master pattern. However, in somesystems, a scanned pattern must meet some threshold degree of matchingor correlation before the denomination of a bill will be called. In suchsystems, bills whose scanned pattern does not sufficiently match one ofthe master patterns are not called, i.e., they are no calls. Accordingto the present embodiment, the system would suggest to the operator thata no call had the denomination associated with the master pattern thatmost closely matched its scanned pattern even though that match wasinsufficient to call the denomination of the bill without theconcurrence of the operator. The operator may accept this suggestion oralter the suggested denomination as described above. For example, in asystem similar to that described in U.S. Pat. No. 5,295,196, the systemmay prompt the operator with the denomination associated with the masterpattern that has the highest correlation with the scanned patternassociated with the given no call bill. For example, if the highestcorrelation for a bill is below 800, the bill is a no call bill. In sucha case, assume the highest correlation is 790 and this correlation isassociated with a $1 bill. When this no call bill is to be reconciled,the system would suggest to the operator that the no call was a $1 bill.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of preset criteria established bythe manufacturer. For example, in FIG. 51a, the denomination indicatingelements are arranged in increasing denominational order. The system maybe designed to default so that a given one of these denominationselection elements is initially highlighted when no call bills are to bereconciled. For example, for each no call the $10 element 2506 d mayinitially be selected. Alternatively, the system may be designed todefault to the first denomination selection element listed, e.g., the $1denomination element 2506 a.

According to another embodiment, a denomination to be prompted to theoperator is determined on the basis of user-defined criteria set by theoperator of a document processing system. For example, in FIG. 51, theoperator may designate the system to default so that a given one of thedenomination indicating elements is initially highlighted when no callbills are to be reconciled. For example, for each no call the operatormay designate that the $10 element 2506 d is to be initially selected.The operator may be permitted to set the default no call denomination,for example, in a set up mode entered into before bills in a stack areprocessed.

In addition to the ways discussed above whereby an initial denominationis prompted to the operator in connection with the reconciling a no callbill, according to other embodiments one or more alternate denominationsare may also be suggested. For example, according to the method wherebythe initial bill is suggested to the operator based on the denominationassociated with a master pattern having the highest correlation relativeto a scanned pattern, if the operator rejects the initial suggestion,the system may be designed to then suggest an alternate denominationbased on the master pattern associated with a genuine bill of adifferent denomination having the next highest correlation value. If theoperator rejects the second suggestion, the system may be designed tothen suggest a second alternate denomination based on the master patternassociated with a genuine bill of a different denomination having thenext highest correlation value, and so on.

For example, suppose the highest correlation was associated with a $1,the second highest correlation was associated with $10, and the thirdhighest correlation was associated with $50. According to thisembodiment, the system would initially suggest that the no call was a$1. If the operator determined the no call was not a $1, the systemwould then suggest that the no call was a $10. If the operatordetermined the no call was not a $10, the system would then suggest thatthe no call was a $50. For example, according to the embodiment of FIGS.53a-b, the system would first ask whether the no call was a $1 bydisplaying the message “$1?” in the display area 2704. If the no callwas a $1, the operator would depress the accept or yes key 2710. If theno call was not a $1 bill, the operator would depress the otherdenomination or no key 2711, in which case, the display area woulddisplay the message “$10?” and so on. Alternatively, the denominationselection elements may be arranged so that their relative order is basedon the correlation results. For example, taking the menu list 2605 ofFIG. 52, the denomination elements may be ordered in the order ofdecreasing correlation values, e.g., according to the previous examplewith the $1 denomination element being listed first, the $10denomination element being listed second, the $50 denomination elementbeing listed third and so on. Alternatively, the denomination elementsmay be listed in the reverse order. According to another embodiment, thedenomination element associated with the highest correlation may belisted in the middle of the list surrounded by the denomination elementsassociated with the second and third highest correlations, and so on.For the above example, the $1 element 2606 a would be listed in themiddle of the menu list 2605 surrounded by the $10 element 2606 d on oneside and the $50 element 2606 f on the other side.

Likewise, the order in which denominations are suggested to the operatorand/or arranged on the control panel may be based on other criteria suchas those described above, such as the prior bill information (e.g., lastbill, last no call, last call denomination), historical information,user-defined order, manufacturer-defined order, and random order. Forexample, using the historical data example given above based on 180 nocalls (100 $5 no calls, 50 $10 no calls, and 30 $20 no calls), the orderthat denominations are suggested to the operator may be first $5, then$10, and then $20. Alternatively, using the last bill information andassuming the following sequence of bills ($2, $5, $5, $5, $20, $10, nocall indicated to be a $50, no call); the system would suggestdenominations for the last no call in the following order: $50, $10,$20, $5, $2. Likewise the order in which the denominations are arrangedon a control panel such as in FIGS. 52 and 50 may be determined based onsuch information, for example, according to the orders described abovein connection with using correlation values. For example, thedenominations may be listed in the prompting order suggested above(e.g., $5, $10, $20 in the historical information example and $50, $10,$20, $5, $2 in the last bill example). Alternatively they may be listedin the reverse order. Alternatively, they may be arranged with the firstsuggested denomination being in the center of the list and beinginitially highlighted or selected. This first suggested denomination maybe surrounded by the second and third suggested denominations which arein turn surrounded by the fourth and fifth suggested denomination, andso on. A default sequence may be used to provide the order for anyremaining denominations which are not dictated by a particular promptingcriteria in a given situation. In the above examples, the denominationsmight be arranged on a menu list in the following orders: $2, $1, $10,$5, $20, $50, $100 for the historical information example and S1, $5,$10, $50, $20, $2, $100. In general, an example of a listing orderaccording to this approach could be from top to bottom: 6th priority orsuggested denomination, 4th, 2nd, 1st, 3rd, 5th, and 7th.

Embodiments arranging the respective order in which denominations aresuggested to the operator and/or displayed on the control panel willlikely aid the operator by reducing the projected number of times theoperator will need to hit one of the scroll keys and/or “OTHER DENOM” or“NO” key.

Now several methods will be described in connection reconciliation of nocalls in multi-output pocket machines after all bills in a stack havebeen processed. Recalling a previous example in which four no call billswere separated out from a stack of fifty bills and the machine haltedafter processing all fifty bills, the system then prompts the operatorto reconcile the value of the four no call bills. For example, assumethe no call bills corresponded to the 5th, 20th, 30th, and 31st bills inthe stack and were $2, $50, $10, and $2 bills respectively. The degreeof intelligence employed by the system in prompting the operator toreconcile the value of the no call bills may vary depending on theparticular embodiment employed. According to one embodiment the operatormay depress or select the denomination selection elements correspondingthe denominations of the no call bills without any prompting from thesystem as to their respective denominations. For example, using thecontrol panel of FIG. 48, the operator would depress the $2 selectionelement 1064 g twice, the $10 selection element 1064 c once, and the $50selection element 1064 e once. The system may or may not inform theoperator that four no call bills must be reconciled and may or may notlimit the operator to entering four denominations. Likewise, in otherembodiments, the operator may use the scroll keys to cause the desireddenomination to become selected and then depress the accept key.Alternatively, a numerical keypad may be provided for permitting theoperator to indicate the number of bills of each denomination that havenot been called. For example, the above example, the operator could usethe scroll keys so that the $2 denomination was selected, then press “2”on the keypad for the number of $2 no calls in the batch, and then pressan enter or accept key. Then the operator could use the scroll keys sothat the $10 denomination was selected, then press “1” on the keypad forthe number of $10 no calls in the batch, and then press an enter oraccept key and so on. The keypad may comprise, for example, keys orselection elements associated with the digits 0-9.

Alternatively, the system may prompt the operator as to the denominationof each no call bill, for example, by employing one of the promptingmethods discussed above, e.g., default, random, user-defined criteria,manufacturer defined criteria, prior bill information (last bill, lastno call, last called denomination), historical information, scanned andmaster comparison information (e.g., highest correlation). For example,the system may serially interrogate the examiner as to the denominationof each no call, for example, the display may initially query “Is 1st nocall a $2?”. Depending on the embodiment of the control panel beingused, the operator could then select “ACCEPT” or “YES” or select the $2denomination selection element, select “OTHER DENOM” or “NO” or use thescroll keys or select the appropriate denomination selection element, orif the operator finds the first bill unacceptable, the operator may putthe first no call bill aside and select “CONT”. The system may thenquery the operator as to the denomination of the second no call bill,and so on. The denomination prompted to the operator would depend on theprompting criteria employed. For example, suppose the prompting criteriawas the denomination of the preceding bill and further suppose that inthe four no call example given above that the first bill was a $2, the2nd bill was a $10, the 3rd bill was a $1, the 4th bill was a $1, the19th bill was a $50, the 29th bill was a $10, and as stated above, the30th bill was a $10. The system would then prompt the operator as towhether the first no call was a $1. Since the first no call is a $2, theoperator would choose “NO”, “OTHER DENOM”, scroll, or hit the $2selection element depending on the embodiment be used. If the “NO” or“OTHER DENOM” key were pressed, the system would review the precedingbills in reverse order and suggest the first denomination encounteredthat had not already been suggested, in this case a $10. If the “NO” or“OTHER DENOM” key were pressed again, the system would then suggest a$2. A predetermined default sequence may be utilized when prior billinformation does not contain the desired denomination. Once the operatorindicates that the first no call is a $2, the system would then promptthe operator as to whether the second no call was a $50. Since thesecond no call was indeed a $50 the operator would choose “ACCEPT”,“YES”, or select the $50 denomination selection element depending on theembodiment chosen. The system would then suggest that the third no callwas a $10 and the operator would similarly indicate acceptance of the$10 suggested denomination. Finally, the system would suggest that thefourth no call was a $10. Since the last no call was a $2, the operatorwould reject the $10 suggestion and indicate that the fourth no callbill was a $2 as described above. The operation of a document processingsystem using a different prompting criteria would proceed in a similarmanner and as described above with respect to each of the describedprompting methods.

While discussed above with respect to no calls, the above embodimentscould also be employed in connection with other types of flagged billssuch as reverse-faced bills, reverse forward/reverse oriented bills,unfit bills, suspect bills, etc.

Referring now to FIG. 55, the touch screen I/O device 2956 includes atouch screen 2960 mounted over a graphics display 2961. In oneembodiment, the display 2961 is a liquid crystal display (LCD) withbacklighting. The display may have, for example, 128 vertical pixels and256 horizontal pixels. The display 2961 contains a built-in charactergenerator which permits the display 2961 to display text and numbershaving font and size pre-defined by the manufacturer of the display.Moreover, a controller such as a CPU is programmed to permit the loadingand display of custom fonts and shapes (e.g., key outlines) on thedisplay 2961. The display 2961 is commercially available as Part No.GMF24012EBTW from Stanley Electric Company, Ltd., Equipment ExportSection, of Tokyo, Japan.

The touch screen 2960 may be an X-Y matrix touch screen forming a matrixof touch responsive points. The touch screen 2960 includes two closelyspaced but normally separated layers of optical grade polyester filmeach having a set of parallel transparent conductors. The sets ofconductors in the two spaced polyester sheets are oriented at rightangles to each other so when superimposed they form a grid. Along theoutside edge of each polyester layer is a bus which interconnects theconductors supported on that layer. In this manner, electrical signalsfrom the conductors are transmitted to the controller. When pressurefrom a finger or stylus is applied to the upper polyester layer, the setof conductors mounted to the upper layer is deflected downward intocontact with the set of conductors mounted to the lower polyester layer.The contact between these sets of conductors acts as a mechanicalclosure of a switch element to complete an electrical circuit which isdetected by the controller through the respective buses at the edges ofthe two polyester layers, thereby providing a means for detecting the Xand Y coordinates of the switch closure. A matrix touch screen 2960 ofthe above type is commercially available from Dynapro Thin FilmProducts, Inc. of Milwaukee, Wis.

As illustrated in FIG. 55, the touch screen 2960 forms a matrix ofninety-six optically transparent switch elements having six columns andsixteen rows. The controller is programmed to divide the switch elementsin each column into groups of three to form five switches in eachcolumn. Actuation of any one of the three switch elements forming aswitch actuates the switch. The uppermost switch element in each columnremains on its own and is unused.

Although the touch screen 2960 uses an X-Y matrix of opticallytransparent switches to detect the location of a touch, alternativetypes of touch screens may be substituted for the touch screen 2960.These alternative touch screens use such well-known techniques ascrossed beams of infrared light, acoustic surface waves, capacitancesensing, and resistive membranes to detect the location of a touch. Thestructure and operation of the alternative touch screens are describedand illustrated, for example, in U.S. Pat. Nos. 5,317,140, 5,297,030,5,231,381, 5,198,976, 5,184,115, 5,105,186, 4,931,782, 4,928,094,4,851,616, 4,811,004, 4,806,709, and 4,782,328, which are incorporatedherein by reference.

The details of conducting a document transaction are illustrated in FIG.56a. The functionality described below may reside at a single locationor may be split across several locations throughout the documentprocessing system, for example, in the full image scanner, at thecentral office computer, and at a personal computer attached to thedocument processing system. The user loads mixed documents at step 11 ainto the machine. This can be accomplished, as discussed above, byplacing the documents in receptacle 16 on the machine. Next, still atstep 11 a, the user initiates the processing of the documents. This canbe accomplished, for example, by having the user press a start key on atouch screen on the communications panel 26, as discussed above, toinitiate a transaction. By “document transaction”, it is meant toinclude not only all documents as described above, but also all forms ofstorage media including all forms of magnetic storage media (e.g., smartcards, debit cards), all forms of optical storage media (e.g., CD disks)and all forms of solid state storage media. Stored on the media is anamount indicating an amount of funds.

The machine attempts to identify the document at step 11 b. If step 11 bfails to identify the document, several alternatives are possibledepending upon the exact implementation chosen for the machine. Forexample, as described previously, if it fails to identify the document,the system can use two canisters and place an unidentified document in a“no read” canister. Alternatively, at step 11 d, the machine can bestopped so that the user can remove the “no read” document immediately.In this alternative, if the document can not be recognized by themachine, the unidentified document is diverted, for example, to a returnslot so that it can be removed from the machine by the user. Also, theimage can be displayed on the teller's video terminal so that the tellercan analyze the image without removing the document. Alternatively, theteller may physically remove the document from the output receptacle,inspect the document and then enter the missing data so the documentcould be processed. After completing these steps, the system returns tostep 11 b to identify the other loaded documents.

In the event that the user wishes to deposit “no read” document that arereturned to the user, the user may key in the value and number of suchdocument and deposit them in an envelope for later verification. Amessage on the display screen may advise the user of this option. Forexample, if four $10 bills are returned, then re-deposited by the userin an envelope, the user may press a “$10” key on the keyboard fourtimes. The user then receives immediate credit for all the documentsdenominated and authenticated by the scanner. Credit for re-deposited“no read” documents is given only after a bank picks up the envelope andmanually verifies the amount. Alternatively, at least preferred userscan be given full credit immediately, subject to later verification, orimmediate credit can be given up to a certain dollar limit. In the caseof counterfeit documents that are not returned to the user, the user canbe notified of the detection of a counterfeit suspect at the machine orlater by a written notice or personal call, depending upon thepreferences of the financial institution.

If step 11 b identifies the documents, next, at step 11 e, the machineattempts to authenticate the documents to determine if the documents aregenuine. The authentication process is described in greater detailbelow. If the documents are not genuine, then the system proceeds to oneof three steps depending upon which option a user chooses for theirmachine. At step 11 f, the system may continue operation and identifythe suspect documents in the stack. In this alternative, a singlecanister is used for all documents, regardless of whether they areverified bills, no reads, or counterfeit suspects. On the other hand, atstep 11 g the machine may outsort the currency, for example, to a rejectbin. The machine may also return the suspect currency at step 11 hdirectly to the user. This is accomplished by diverting the currency tothe return slot. Also, the machine maintains a count of the total numberof counterfeit documents. If this total reaches a certain thresholdvalue, an alarm condition will be generated. The alarm condition may behandled, for example, by turning on a light on the machine or byalerting the central office.

As mentioned above, the system may use a single canister to hold thedocuments. If a single canister system is used, then the variousdocuments are identified within the single canister by placing differentcolored markers at the top of different documents. These documents areinserted into the bill transport path so they follow the respectivebills to be inserted into the canister. Specifically, a first marker,e.g., a marker of a first color, is inserted to indicate the document isa counterfeit suspect that is not to be returned to the user. A secondtype of marker, e.g., a marker of a second color, can be inserted toindicate that the document is a counterfeit suspect. A third type ofmarker, e.g., of a third color, is inserted to indicate that a markedbatch of documents represents a deposit whose verified amount did notagree with the user's declared balance. Because this third type ofmarker identifies a batch of documents instead of a single document, itis necessary to insert a marker at both the beginning and end of amarked batch. The marker could vary in size, contain bar-codes, or varyin color to easily identify different types of documents such as checksand currency.

If the document is authenticated, the total count B_(total) and bincount B_(counti) (where “i” is the “ith” bin) are incremented at step 11i. The total count B_(total) is used by the machine to establish theamount deposited by the user and the bin counts are used to determinethe amount of documents in a particular bin.

The machine then determines whether sorting is required at step 11 j. Ifthe answer is affirmative, then the document is sorted by denominationat step 11 k. Rather than using single or double bins, as describedabove, this option includes a bin for each denomination and a bin foreach type of document such as checks and loan coupons. A bin would alsobe designated to receive a combination of documents. For example, onebin could be designated to bank proof-of-deposit documents such aschecks, loan coupons, and savings deposit slips. Sorting is accomplishedby a sorting and counting module which sorts the documents placing eachdenomination in a specific bin. The sorting algorithm used can be anythat is well known in the art.

After sorting at step 11 k or if the answer to step 11 j is negative.the machine proceeds to step 11 l. At step 11 l, the machine tests ifthe document bin in use is full. That is, the machine comparesB_(counti) to the maximum allowed for a bin. If it is full, at step 11m, the machine determines if there is an empty document bin. If there isno empty document bin available, at step 11 m, the machine stops. Thedocument is emptied at step 11 n. If an empty document bin exists, themachine switches to the empty bin and places the document into that binat step 11 p.

At step 11 o, the system determines when the last document in thedeposited stack of documents has been counted. If counting is complete,the machine is stopped at step 11 q.

The transport mechanism may also include an escrow holding area wherethe document being processed in a pending deposit transaction is helduntil the transaction is complete. Thus, from step 11 q, the systemproceeds to step 11 s, to determine if escrow has been enabled. Ifescrow has not been enabled, the count of the machine is accepted atstep 11 u and the total amount B_(total) is posted to the user at step 1v. If escrow has been enabled, at step 11 r, the user is given thechoice of accepting the count. If the user decides not to accept thecount, at step 11 t, the document is returned to the user. From step 11t, the machine proceeds to step 11 a where the user is given anotherchance of counting the document. If the user decides to accept the countat step 11 r, the machine proceeds to step 11 u where the count isaccepted and step 1 v where the total count is displayed to the user. Atthis point, the document counting transaction is complete.

A coin transaction is described in greater detail in FIG. 56f. As shown,a customer loads mixed coins into the system at step 12 a. The coins aresorted, authenticated, and bagged one at a time. At step 12 b, themachine sorts the coin. The sorting process is described in greaterdetail below. At step 12 c, the machine determines if the coin isauthentic. This process is also described in greater detail below. Ifthe coin is not authentic, the machine outsorts the coin to a reject binat step 12 d and then proceeds to step 12 i and determines if countingand sorting is complete.

If the coin is authentic, the coin count C_(total) and bag countC_(bagi) (where “i” represents the “ith” bag) is incremented by one atstep 12 e. The system count C_(total) represents the total value of thecoins deposited while the bag count represents the number of coins in abag. After sorting and authenticating the coin, the system attempts toplace the coin in a bag at step 12 h. All coins can be placed in one bagor one bag per denomination can be used. Alternatively, any number ofdenominations, for example, two, could be placed in a bag. At step 12 h,the system checks to see if the limit of the bag has been reached. Thatis, the system compares C_(bagi) to the predetermined limit for a bag.If the limit has been reached for the bag in current use (e.g., bag A),the machine next checks to see if another bag (e.g., bag B) is full atstep 12 f. If bag B is full, the machine is stopped and an operatorempties the bag at step 12 g. If the other bag (e.g., bag B) is notfull, then at step 12 i the machine switches to this bag and the coin isplaced there. The machine then proceeds to step 12 j where a test isperformed to determine if counting is complete.

At step 12 j, the machine determines if sorting is complete. This isaccomplished by sensing whether there are additional coins to sort inthe coin bin. If sorting is not complete, the system continues at step12 b by counting and sorting the next coin.

If sorting has been completed, at step 12 k the machine checks whetherthe escrow option has been enabled. If it has, at step 121, the machineasks the customer whether they wish to accept the count. If the customerreplies in the affirmative, at step 12 m the machine accepts the countC_(total) and posts the total to the customer. If the customer replieswith a negative answer at step 121, then the machine returns the coinsto the customer at step 12 n and the counting is complete.

If escrow has not been enabled, the machine checks at step 12 o to seeif stop has been pressed. If it has, the machine stops. If stop has notbeen pressed, then the machine waits for a certain period of time totime out at step 12 p and stops when this time period has been reached.

The operation of the distribution step is now described in greaterdetail. As mentioned previously, at step 10 c of flowchart of FIG. 2,the user allocates the amount deposited, whether the amount deposited isin the form of bills or coin. This step is illustrated in detail inFIGS. 56b, 56 c, and 56 d.

The machine inputs the funds at step 15 k and sets S_(total) (the totalfunds to be allocated) equal to either B_(total) at step 15 l. The userhas the choice of adding more funds at step 15 m. If the answer isaffirmative, more funds are added. This process is described in detailbelow. If the answer is negative, the machine proceeds to step 13 a withthe user selecting the amount and destination for the distribution offunds. The user is prompted by screen 52 to make these selections.

The user then has several options for distribution destinations. Theuser can choose to proceed to step 13 b where an amount is transferredonto some storage media, for example, a smart card, and the storagemedia is automatically dispensed to the user. Another option, at step 13c, is to have an amount distributed to a user account, for example, anaccount in a grocery store. Another choice is to distribute an amount inthe form of loose document to the user at step 13 d or loose coin atstep 13 e. The user can also choose to distribute the amount tocreditors at step 13 f or make payment of fees to creditors at step 13g. The user might make payment of fees to financial institutions at step13 h. These could include mortgage payments, for example. The user canchoose to add the amount to some form of storage media, for example, asmart card, at step 13 i. The user might also choose to dispensestrapped document at step 13 j, rolled coin at step 13 k, in the form oftokens, coupons, or user script at step 131, dispense a bank check ormoney order at step 13 m, or dispense a check dawn on a customer accountat step 13 n.

For some of the distribution selections, e.g. distribution of loosebills, the user may wish to have certain denominations returned to himor may wish to accept a machine allocation. For example, the user maychoose to allocate a $100 deposit as four $20 bills, one $10 bill, andtwo $5 bills rather than accepting the default machine allocation. Thosedistributions where the user has a choice of allocating the depositthemselves or accepting a machine allocation, follow path A. If themachine proceeds via path A, at step 14 a the user is asked whether theywish to allocate the amount. If the answer is affirmative, the user willthen decide the allocation at step 14 c. However, if the answer at step14 a is negative, then the machine decides the allocation at step 14 b.Machine allocation is appropriate for dispensing all forms of bills,coins, tokens, coupons, user script and to storage media.

On the other hand, some distributions, e.g. deposits to bank accounts,require the user to allocate the deposit. For example, for a $500deposit, a user may allocate $250 to a savings account and $250 to achecking account. Those distributions where the user is required toallocate the amount deposited follow path B. If the machine proceeds viapath B, at step 14 c the user decides the allocation. The machine thencontinues at step 14 c.

After steps 14 c or 14 d, the machine proceeds to step 14 d where theamount distributed is subtracted from the total amount deposited. Atstep 14 e, the machine determines whether there is anything left todistribute after the subtraction. If the answer is affirmative, themachine proceeds to step 13 a where the user again decides a place todistribute the amount allocated.

At step 14 f, the user decides whether they wish to close thetransaction. If they do, the transaction is closed. The closingcompletes step 10 c of FIG. 2. On the other hand, they may not wish toend the transaction. For example, they may wish to add more cash, coins,or credit from other sources. If this is the case, the machine proceedsto step 15 a of FIG. 56d.

At step 15 a, the user decides which additional source of funds is to beused. The user could choose, at step 15 b, to withdraw funds from acredit line, for example, from a credit card or bank. The user couldchoose to deposit more bills at step 15 d. These steps were discussedabove. The user could also choose to write a check and have this scannedin at step 15 e, take a value from a form of storage media, for example,a smart card, at step 15 f, add values from food stamps at step 15 g,count credit card slips at step 15 h or coupon slips at step 15 i, orwithdraw from a user account at step 15 j.

At step 15 k, these additional funds are input into the system. Forexample, the algorithm illustrated in FIG. 56a is used to input anamount of additional funds from newly deposited bills. At step 15 l,this amount is added to the total amount of funds. At step 15 m, theuser is given the choice of adding more funds. If the answer isaffirmative, the system returns to step 15 a where the user declares thesource of additional funds. If the answer is negative, the machinereturns to step 13 a in FIG. 56b where the user is again asked todetermine the distribution of the funds. The machine then proceeds asdescribed above.

As described, the user can initiate a document transaction by directlydepositing funds from some form of storage media including all forms ofmagnetic, optical, and solid-state media. In the case of a documenttransaction using storage media, the user may insert their media into amedia reader so that it may be read. The machine then may prompt theuser for the amount to be removed from the media and distributed toother sources. Conversely, the machine might remove all the fundsavailable from the media. In any case, once the deposit amount has beenremoved from the media, the machine proceeds to step 15 k in FIG. 56d.The remaining steps are the same as described above.

Also as described above, the user can initiate a transaction bydepositing funds from an outside source. By outside source, it is meantto include a credit card account, bank account, store account, or othersimilar accounts. The user may initiate a transaction by using the touchscreen to enter account information, such as the account number and PINnumber to access the account. The user might also initiate thetransaction by moving an account identification card through a mediareader, then using the communications panel to enter other data such asthe amount to be withdrawn from the account. Then, the system proceedsto step 15 k of FIG. 56d. The remaining steps are described are the sameas described above.

The alternate funds distribution algorithm is illustrated in FIG. 56e.At step 17 a, the user indicates whether there are any more funds toprocess. If the answer is affirmative, at step 17 b, the machineprocesses more funds. If the answer is negative, then at step 17 c, thedispensing unit distributes the funds according to its programming.Operation of the machine then stops.

As described above, the processing system has the advantage of beingable to process mixed currency or documents utilizing full imagescanning and a discriminator. The deposits in the system are processedsubstantially immediately. In addition, the full image of the scanneddocument can be communicated to a central office from which two-waycommunication with a system at a remote location is allowed. Finally,the processing system provides all the benefits of an automated tellermachine.

An alternate embodiment of a control panel 3002 is shown in FIG. 57a. Aset of keys 3004 is used to enter numeric data which is shown on thescreen which appears to be missing from bill 3006. Alternatively, theuser may enter denomination information using keys 3008 which relate todenominations which appear on the screen. In yet another embodiment ofthe control panel, a touch screen 3020 is used to enter no-callinformation concerning bill 3022. The user can enter the missinginformation using a keypad 3026 or denomination keys 3024 which appearon the touch screen. Additionally, the user could use a standardalphanumeric keyboard to complete the document image as required.Alternatively, if a personal computer terminal is used, a mouse could beused identify and select appropriate fields. For example, if thedocument were a check, the unidentified field may be the signature fieldor the amount field. The user would “click” this field. A second screenwould appear on the terminal where the missing data would be entered.These routines could be customer-specific based upon the customer'sneeds.

As stated before, the system may include a coin sorting anddiscrimination module 19. FIGS. 58-61 illustrate a disc-type coin sorterused in coin sorting and discrimination module 19 that uses acoin-driving member having a resilient surface for moving coins along ametal coin-guiding surface of a stationary coin-guiding member.Alternatively, the coin sorter may be a rail sorter such as thedisclosed in U.S. Pat. No. 5,163,868 or U.S. Pat. No. 5,114,381, both ofwhich are incorporated by reference herein in their entirety. The sortermay also be a core sorter such as that disclosed in U.S. Pat. No.2,835,260, sifter-type sorter such as that disclosed in U.S. Pat. No.4,360,034, or any type of coin-counting disk such as that described inU.S. Pat. No. 4,543,969, all of which are incorporated by referenceherein in their entirety. Additionally, the coin sorter may be a drumsorter, dual-disc sorter, or any other coin sorter as is known to thoseskilled in the art. Alternatively, the simple coin sorter with coindiscrimination can be used to verify the deposit of coin. Such sortersare described in U.S. Pat. No. 2,669,998, U.S. Pat. No. 2,750,949, andU.S. Pat. No. 5,299,977, all of which are incorporated by referenceherein in their entirety. The coin-driving member is a rotating disc,and the coin-guiding member is a stationary sorting head. As can be seenin FIG. 58, a hopper 1510 receives coins of mixed denominations andfeeds them through central openings in a housing 1511 and a coin-guidingmember in the form of an annular sorting head or guide plate 1512 insideor underneath the housing. As the coins pass through these openings,they are deposited on the top surface of a coin-driving member in theform of a rotatable disc 1513. This disc 1513 is mounted for rotation ona stub shaft (not shown) and driven by an electric motor 1514 mounted toa base plate 1515. The disc 1513 comprises a resilient pad 1516 bondedto the top surface of a solid metal disc 1517.

The top surface of the resilient pad 1516 is preferably spaced from thelower surface of the sorting head 1512 by a gap of about 0.005 inches(0.13 mm). The gap is set around the circumference of the sorting head1512 by a three point mounting arrangement including a pair of rearpivots 1518, 1519 loaded by respective torsion springs 1520 which tendto elevate the forward portion of the sorting head. During normaloperation, however, the forward portion of the sorting head 1512 is heldin position by a latch 1522 which is pivotally mounted to the frame 1515by a bolt 1523. The latch 1522 engages a pin 1524 secured to the sortinghead. For gaining access to the opposing surfaces of the resilient pad1516 and the sorting head, the latch is pivoted to disengage the pin1524, and the forward portion of the sorting head is raised to an upwardposition (not shown) by the torsion springs 1520.

As the disc 1513 is rotated, the coins 1525 deposited on the top surfacethereof tend to slide outwardly over the surface of the pad due tocentrifugal force. The coins 1525, for example, are initially displacedfrom the center of the disc 1513 by a cone 1526, and therefore aresubjected to sufficient centrifugal force to overcome their staticfriction with the upper surface of the disc. As the coins moveoutwardly, those coins which are lying flat on the pad enter the gapbetween the pad surface and the guide plate 1512 because the undersideof the inner periphery of this plate is spaced above the pad 16 by adistance which is about the same as the thickness of the thickest coin.As further described below, the coins are sorted into their respectivedenominations, and the coins for each denomination issue from arespective exit slot, such as the slots 1527, 1528, 1529, 1530, 1531 and1532 (see FIGS. 58 and 59) for dimes, pennies, nickels, quarters,dollars, and half-dollars, respectively. In general, the coins for anygiven currency are sorted by the variation in diameter for the variousdenominations.

Preferably most of the aligning, referencing, sorting, and ejectingoperations are performed when the coins are pressed into engagement withthe lower surface of the sorting head 1512. In other words, the distancebetween the lower surfaces of the sorting head 1512 with the passagesconveying the coins and the upper surface of the rotating disc 1513 isless than the thickness of the coins being conveyed. As mentioned above,such positive control permits the coin sorter to be quickly stopped bybraking the rotation of the disc 1513 when a preselected number of coinsof a selected denomination have been ejected from the sorter. Positivecontrol also permits the sorter to be relatively compact yet operate athigh speed. The positive control, for example, permits the single filestream of coins to be relatively dense, and ensures that each coin inthis stream can be directed to a respective exit slot.

Turning now to FIG. 59, there is shown a bottom view of the preferredsorting head 1512 including various channels and other means especiallydesigned for high-speed sorting with positive control of the coins, yetavoiding the galling problem. It should be kept in mind that thecirculation of the coins, which is clockwise in FIG. 58, appearscounterclockwise in FIG. 59 because FIG. 59 is a bottom view. Thevarious means operating upon the circulating coins include an entranceregion 1540, means 1541 for stripping “shingled” coins, means 1542 forselecting thick coins, first means 1544 for recirculating coins, firstreferencing means 1545 including means 1546 for recirculating coins,second referencing means 1547, and the exit means 1527, 1528, 1529,1530, 1531 and 1532 for six different coin denominations, such as dimes,pennies, nickels, quarters, dollars and half-dollars. The lowermostsurface of the sorting head 1512 is indicated by the reference numeral1550.

Considering first the entrance region 1540, the outwardly moving coinsinitially enter under a semi-annular region underneath a planar surface1561 formed in the underside of the guide plate or sorting head 1512.Coin C1, superimposed on the bottom plan view of the guide plate in FIG.59 is an example of a coin which has entered the entrance region 1540.Free radial movement of the coins within the entrance region 1540 isterminated when they engage a wall 1562, though the coins continue tomove circumferentially along the wall 1562 by the rotational movement ofthe pad 1516, as indicated by the central arrow in the counterclockwisedirection in FIG. 59. To prevent the entrance region 1540 from becomingblocked by shingled coins, the planar region 1561 is provided with aninclined surface 1541 forming a wall or step 1563 for engaging theuppermost coin in a shingled pair. In FIG. 59, for example, an uppercoin C2 is shingled over a lower coin C3. As further shown in FIG. 60,movement of the upper coin C2 is limited by the wall 1563 so that theupper coin C2 is forced off of the lower coin C3 as the lower coin ismoved by the rotating disc 1513.

Returning to FIG. 59, the circulating coins in the entrance region 1540,such as the coin C1, are next directed to the means 1542 for selectingthick coins. This means 1542 includes a surface 1564 recessed into thesorting head 1512 at a depth of 0.070 inches (1.78 mm) from thelowermost surface 1550 of the sorting head. Therefore, a step or wall1565 is formed between the surface 1561 of the entrance region 1540 andthe surface 1564. The distance between the surface 1564 and the uppersurface of the disc 1513 is therefore about 0.075 inches so thatrelatively thick coins between the surface 1564 and the disc 1513 areheld by pad pressure. To initially engage such thick coins, an initialportion of the surface 1564 is formed with a ramp 1566 located adjacentto the wall 1562. Therefore, as the disc 1513 rotates, thick coins inthe entrance region that are next to the wall 1562 are engaged by theramp 1566 and thereafter their radial position is fixed by pressurebetween the disc and the surface 1564. Thick coins which fail toinitially engage the ramp 1566, however, engage the wall 1565 and aretherefore recirculated back within the central region of the sortinghead. This is illustrated, for example, in FIG. 61 for the coin C4. Thisinitial selecting and positioning of the thick coins prevents misalignedthick coins from hindering the flow of coins to the first referencingmeans 1545.

Returning now to FIG. 59, the ramp 1566 in the means 1542 for selectingthe thick coins can also engage a pair or stack of thin coins. Such astack or pair of thin coins will be carried under pad pressure betweenthe surface 1564 and the rotating disc 1513. In the same manner as athick coin, such a pair of stacked coins will have its radial positionfixed and will be carried toward the first referencing means 1545. Thefirst means 1545 for referencing the coins obtains a single-file streamof coins directed against the outer wall 1562 and leading up to a ramp1573.

Coins are introduced into the referencing means 1545 by the thinnercoins moving radially outward via centrifugal force, or by the thickercoin(s) C52 a following concentricity via pad pressure. The stackedcoins C58 a and C50 a are separated at the inner wall 1582 such that thelower coin C58 a is carried against surface 1572 a. The progression ofthe lower coin C58 a is depicted by its positions at C58 b, C58 c, C58d, and C58 e. More specifically, the lower coin C58 becomes engagedbetween the rotating disc 1513 and the surface 1572 in order to carrythe lower coin to the first recirculating means 1544, where it isrecirculated by the wall 1575 at positions C58 d and C58 e. At thebeginning of the wall 1582, a ramp 1590 is used to recycle coins notfully between the outer and inner walls 1562 and 1582 and under thesorting head 1512. As shown in FIG. 59, no other means is needed toprovide a proper introduction of the coins into the referencing means1545.

The referencing means 1545 is further recessed over a region 1591 ofsufficient length to allow the coins C54 of the widest denomination tomove to the outer wall 1562 by centrifugal force. This allows coins C54of the widest denomination to move freely into the referencing means1545 toward its outer wall 1562 without being pressed between theresilient pad 1516 and the sorting head 1512 at the ramp 1590. The innerwall 1582 is preferably constructed to follow the contour of the recessceiling. The region 1591 of the referencing recess 1545 is raised intothe head 1512 by ramps 1593 and 1594, and the consistent contour at theinner wall 1582 is provided by a ramp 1595.

The first referencing means 1545 is sufficiently deep to allow coins C50having a lesser thickness to be guided along the outer wall 1562 bycentrifugal force, but sufficiently shallow to permit coins C52, C54having a greater thickness to be pressed between the pad 1516 and thesorting head 1512, so that they are guided along the inner wall 1582 asthey move through the referencing means 1545. The referencing recess1545 includes a section 1596 which bends such that coins C52, which aresufficiently thick to be guided by the inner wall 1582 but have a widthwhich is less than the width of the referencing recess 1545, are carriedaway from the inner wall 1582 from a maximum radial location 1583 on theinner wall toward the ramp 1573.

This configuration in the sorting head 1512 allows coins of alldenominations to converge at a narrow ramped finger 1573 a on the ramp1573, with coins C54 having the largest width being carried between theinner and outer walls via the surface 1596 to the ramped finger 1573 aso as to bring the outer edges of all coins to a generally common radiallocation. By directing the coins C50 radially inward along the latterportion of the outer wall 1562, the probability of coins being offsetfrom the outer wall 1562 by adjacent coins and being led onto the rampedfinger 1573 a is significantly reduced. Any coins C50 which are slightlyoffset from the outer wall 1562 while being led onto the ramp finger1573 a may be accommodated by moving the edge 1551 of exit slot 1527radially inward, enough to increase the width of the slot 1527 tocapture offset coins C50 but to prevent the capture of coins of thelarger denominations. For sorting Dutch coins, the width of the rampfinger 1573 a may be about 0.140 inch. At the terminal end of the ramp1573, the coins become firmly pressed into the pad 16 and are carriedforward to the second referencing means 1547.

A coin such as the coin C50 c will be carried forward to the secondreferencing means 1547 so long as a portion of the coin is engaged bythe narrow ramped finger 1573 a on the ramp 1573. If a coin is notsufficiently close to the wall 1562 so as to be engaged by this rampedfinger 1573 a, then the coin strikes a wall 1574 defined by the secondrecirculating means 1546, and that coin is recirculated back to theentrance region 1540.

The first recirculating means 1544, the second recirculating means 1546and the second referencing means 1547 are defined at successivepositions in the sorting head 1512. It should be apparent that the firstrecirculating means 1544, as well as the second recirculating means1546, recirculate the coins under positive control of pad pressure. Thesecond referencing means 1547 also uses positive control of the coins toalign the outermost edge of the coins with a gaging wall 1577. For thispurpose, the second referencing means 1547 includes a surface 1576, forexample, at 0.110 inches (1.27 mm) from the bottom surface of thesorting head 1512, and a ramp 1578 which engages the inner edge portionsof the coins, such as the coin C50 d.

As best shown in FIG. 59, the initial portion of the gaging wall 1577 isalong a spiral path with respect to the center of the sorting head 1512and the sorting disc 1513, so that as the coins are positively driven inthe circumferential direction by the rotating disc 1513, the outer edgesof the coins engage the gaging wall 1577 and are forced slightlyradially inward to a precise gaging radius, as shown for the coin C16 inFIG. 60. FIG. 60 further shows a coin C17 having been ejected from thesecond recirculating means 1546.

Referring back to FIG. 59, the second referencing means 1547 terminateswith a slight ramp 1580 causing the coins to be firmly pressed into thepad 1516 on the rotating disc with their outermost edges aligned withthe gaging radius provided by the gaging wall 1577. At the terminal endof the ramp 1580 the coins are gripped between the guide plate 1512 andthe resilient pad 1516 with the maximum compressive force. This ensuresthat the coins are held securely in the new radial position determinedby the wall 1577 of the second referencing means 1547.

The sorting head 1512 further includes sorting means comprising a seriesof ejection recesses 1527, 1528, 1529, 1530, 1531 and 1532 spacedcircumferentially around the outer periphery of the plate, with theinnermost edges of successive slots located progressively farther awayfrom the common radial location of the outer edges of all the coins forreceiving and ejecting coins in order of increasing diameter. The widthof each ejection recess is slightly larger than the diameter of the cointo be received and ejected by that particular recess, and the surface ofthe guide plate adjacent the radially outer edge of each ejection recesspresses the outer portions of the coins received by that recess into theresilient pad so that the inner edges of those coins are tilted upwardlyinto the recess. The ejection recesses extend outwardly to the peripheryof the guide plate so that the inner edges of these recesses guide thetilted coins outwardly and eventually eject those coins from between theguide plate 1512 and the resilient pad 1516.

The innermost edges of the ejection recesses are positioned so that theinner edge of a coin of only one particular denomination can enter eachrecess, the coins of all other remaining denominations extend inwardlybeyond the innermost edge of that particular recess so that the inneredges of those coins cannot enter the recess.

For example, the first ejection recess 1527 is intended to dischargeonly dimes, and thus the innermost edge 1551 of this recess is locatedat a radius that is spaced inwardly from the radius of the gaging wall1577 by a distance that is only slightly greater than the diameter of adime. Consequently, only dimes can enter the recess 1527.

Because the outer edges of all denominations of coins are located at thesame radial position when they leave the second referencing means 1547,the inner edges of the pennies, nickels, quarters, dollars and halfdollars all extend inwardly beyond the innermost edge of the recess1527, thereby preventing these coins from entering that particularrecess.

At recess 1528, the inner edges of only pennies are located close enoughto the periphery of the sorting head 1512 to enter the recess. The inneredges of all the larger coins extend inwardly beyond the innermost edge1552 of the recess 1528 so that they remain gripped between the guideplate and the resilient pad. Consequently, all the coins except thepennies continue to be rotated past the recess 1528.

Similarly, only nickels enter the ejection recess 1529, only thequarters enter the recess 1530, only the dollars enter the recess 1531,and only the half dollars enter the recess 1532.

Because each coin is gripped between the sorting head 1512 and theresilient pad 16 throughout its movement through the ejection recess,the coins are under positive control at all times. Thus, any coin can bestopped at any point along the length of its ejection recess, even whenthe coin is already partially projecting beyond the outer periphery ofthe guide plate. Consequently, no matter when the rotating disc isstopped (e.g., in response to the counting of a preselected number ofcoins of a particular denomination), those coins which are alreadywithin the various ejection recesses can be retained within the sortinghead until the disc is re-started for the next counting operation.

One of six proximity sensors S₁-S₆ is mounted along the outboard edge ofeach of the six exit channels 1527-1532 in the sorting head for sensingand counting coins passing through the respective exit channels. Bylocating the sensors S₁-S₆ in the exit channels, each sensor isdedicated to one particular denomination of coin, and thus it is notnecessary to process the sensor output signals to determine the coindenomination. The effective fields of the sensors S₁-S₆ are all locatedjust outboard of the radius at which the outer edges of all coindenominations are gaged before they reach the exit channels 1527-1532,so that each sensor detects only the coins which enter its exit channeland does not detect the coins which bypass that exit channel. Only thelargest coin denomination (e.g., U.S. half dollars) reaches the sixthexit channel 1532, and thus the location of the sensor in this exitchannel is not as critical as in the other exit channels 1527-1531.

In addition to the proximity sensors S1-S6, each of the exit channels1527-1532 also includes one of six coin discrimination sensors D1-D6.These sensors D1-D6 are the eddy current sensors, and will be describedin more detail below in connection with FIGS. 62-65 of the drawings.

When one of the discrimination sensors detects a coin material that isnot the proper material for coins in that exit channel, the disc may bestopped by de-energizing or disengaging the drive motor and energizing abrake. The suspect coin may then be discharged by jogging the drivemotor with one or more electrical pulses until the trailing edge of thesuspect coin clears the exit edge of its exit channel. The exact discmovement required to move the trailing edge of a coin from its sensor tothe exit edge of its exit channel can be empirically determined for eachcoin denomination and then stored in the memory of the control system.An encoder on the sorter disc can then be used to measure the actualdisc movement following the sensing of the suspect coin, so that thedisc can be stopped at the precise position where the suspect coinclears the exit edge of its exit channel, thereby ensuring that no coinsfollowing the suspect coin are discharged.

Turning now to FIGS. 62-65, one embodiment of the present inventionemploys an eddy current sensor 1710 to perform as the coin handlingsystem's coin discrimination sensors D1-D6. The eddy current sensor 1710includes an excitation coil 1712 for generating an alternating magneticfield used to induce eddy currents in a coin 1714. The excitation coil1712 has a start end 1716 and a finish end 1718. In this embodiment, ana-c excitation coil voltage V_(ex), e.g., a sinusoidal signal of 250 KHzand 10 volts peak-to-peak, is applied across the start end 1716 and thefinish end 1718 of the excitation coil 1712. The alternating voltageV_(ex) produces a corresponding current in the excitation coil 1712which in turn produces a corresponding alternating magnetic field. Thealternating magnetic field exists within and around the excitation coil1712 and extends outwardly to the coin 1714. The magnetic fieldpenetrates the coin 1714 as the coin is moving in close proximity to theexcitation coil 1712, and eddy currents are induced in the coin 1714 asthe coin moves through the alternating magnetic field. The strength ofthe eddy currents flowing in the coin 1714 is dependent on the materialcomposition of the coin, and particularly the electrical resistance ofthat material. Resistance affects how much current will flow in the coin1614 according to Ohm's Law (voltage=current*resistance).

The eddy currents themselves also produce a corresponding magneticfield. A proximal detector coil 1722 and a distal coil 1724 are disposedabove the coin 1714 so that the eddy current-generated magnetic fieldinduces voltages upon the coils 1722, 1724. The distal detector coil1724 is positioned above the coin 1714, and the proximal detector coil1722 is positioned between the distal detector coil 1724 and the passingcoin 1714.

In one embodiment, the excitation coil 1712, the proximal detector coil1722 and the distal detector coil 1724 are all wound in the samedirection (either clockwise or counterclockwise). The proximal detectioncoil 1722 and the distal detector coil 1724 are wound in the samedirection so that the voltages induced on these coils by the eddycurrents are properly oriented.

The proximal detection coil 1722 has a starting end 1726 and a finishend 1728. Similarly, the distal coil 1724 has a starting end 1730 and afinish end 1632. In order of increasing distance from the coin 1614, thedetector coils 1722, 1724 are positioned as follows: finish end 1728 ofthe proximal detector coil 1722, start end 1726 of the proximal detectorcoil 1722, finish end 1732 of the distal detector coil 1724 and startend 1730 of the distal detector coil 1724. The finish end 1728 of theproximal detection coil 1722 is connected to the finish end 1732 of thedistal detector coil 1724 via a conductive wire 1734. It will beappreciated by those skilled in the art that other detector coil 1722,1724 combinations are possible. For example, in an alternativeembodiment the proximal detection coil 1722 is wound in the oppositedirection of the distal detection coil 1724. In this case the start end1726 of the proximal coil 1722 is connected to the finish end 1732 ofthe distal coil 1724.

Eddy currents in the coin 1714 induce voltages V_(prox) and V_(dist)respectively on the detector coils 1722, 1724. Likewise, the excitationcoil 1712 also induces a common-mode voltage V_(com) on each of thedetector coils 1722, 1724. The common-mode voltage V_(com) iseffectively the same on each detector coil due to the symmetry of thedetector coils' physical arrangement within the excitation coil 1712.Because the detector coils 1722, 1724 are wound and physically orientedin the same direction and connected at their finish ends 1728, 1732, thecommon-mode voltage V_(com) induced by the excitation coil 1712 issubtracted out, leaving only a difference voltage V_(diff) correspondingto the eddy currents in the coin 1714. This eliminates the need foradditional circuitry to subtract out the common-mode voltage V_(com).The common-mode voltage V_(com) is effectively subtracted out becauseboth the distal detection coil 1724 and the proximal detection coil 1722receive the same level of induced voltage V_(com) from the excitationcoil 1712.

Unlike the common-mode voltage, the voltages induced by the eddy currentin the detector coils are not effectively the same. This is because theproximal detector coil 1722 is purposely positioned closer to thepassing coin than the distal detector coil 1724. Thus, the voltageinduced in the proximal detector coil 1722 is significantly stronger,i.e., has greater amplitude, than the voltage induced in the distaldetector coil 1724. Although the present invention subtracts the eddycurrent-induced voltage on the distal coil 1724 from the eddycurrent-induced voltage on the proximal coil 1722, the voltage amplitudedifference is sufficiently great to permit detailed resolution of theeddy current response.

As seen in FIG. 62, the excitation coil 1712 is radially surrounded by amagnetic shield 1734. The magnet shield 1734 has a high level ofmagnetic permeability in order to help contain the magnetic fieldsurrounding the excitation coil 1712. The magnetic shield 1734 has theadvantage of preventing a stray magnetic field from interfering withother nearby eddy current sensors. The magnetic shield is itselfradially surrounded by a steel outer case 1736.

In one embodiment the excitation coil utilizes a cylindrical ceramic(e.g., alumina) core 1738. Alumina has the advantages of beingimpervious to humidity and providing a good wear surface. It isdesirable that the core 1748 be able to withstand wear because it maycome into frictional contact with the coin 1714. Alumina withstandsfrictional contact well because of its high degree of hardness, i.e.,approximately 9 on mohs scale.

To form the eddy current sensor 1510, the detection coils 1722, 1724 arewound on a coil form (not shown). A preferred form is a cylinder havinga length of 0.5 inch, a maximum diameter of 0.2620 inch, a minimumdiameter of 0.1660 inch, and two grooves of 0.060 inch width spacedapart by 0.060 inch and spaced from one end of the form by 0.03 inch.Both the proximal detection coil 1722 and the distal detector coil 1724have 350 turns of #44 AWG enamel covered magnet wire layer wound togenerally uniformly fill the available space in the grooves. Each of thedetector coils 1722, 1724 are wound in the same direction with thefinish ends 1728, 1732 being connected together by the conductive wire1734. The start ends 1726, 1730 of the detector coils 1722, 1724 areconnected to separately identified wires in a connecting cable.

The excitation coil 1712 is a generally uniformly layer wound on acylindrical alumina ceramic coil form having a length of 0.5 inch, anoutside diameter of 0.2750 inch, and a wall thickness of 0.03125 inch.The excitation coil 1712 is wound with 135 turns of #42 AWGenamel-covered magnet wire in the same direction as the detector coils1722, 1724. The excitation coil voltage V_(ex) is applied across thestart end 1716 and the finish end 1718.

After the excitation coil 1712 and detector coils 1722, 1724 are wound,the excitation coil 1712 is slipped over the detector coils 1722, 1724around a common center axis. At this time the sensor 1710 is connectedto a test oscillator (not shown) which applies the excitation voltageV_(ex) to the excitation coil 1712. The excitation coil's position isadjusted along the axis of the coil to give a null response from thedetector coils 1722, 1724 on an a-c. voltmeter with no metal near thecoil windings.

Then the magnetic shield 1644 is the slipped over the excitation coil1712 and adjusted to again give a null response from the detector coils1722, 1724.

The magnetic shield 1744 and coils 1712, 1722, 1724 within the magneticshield 1744 are then placed in the steel outer case 1746 andencapsulated with a polymer resin (not shown) to “freeze” the positionof the magnetic shield 1744 and coils 1712, 1722, 1724.

After curing the resin, an end of the eddy current sensor 1710 nearestthe proximal detector coil 1722 is sanded and lapped to produce a flatand smooth surface with the coils 1712, 1722 slightly recessed withinthe resin.

In order to detect the effect of the coin 1714 on the voltages inducedupon the detector coils 1722, 1724, it is preferred to use a combinationof phase and amplitude analysis of the detected voltage. This type ofanalysis minimizes the effects of variations in coin surface geometryand in the distance between the coin and the coils.

The voltage applied to the excitation coil 1712 causes current to flowin the coil 1712 which lags behind the voltage 1720. For example, thecurrent may lag the voltage 1720 by 90 degrees in a superconductivecoil. In effect, the coin's 1714 eddy currents impose a resistive losson the current in the excitation coil 1712. Therefore, the initial phasedifference between the voltage and current in the excitation coil 1712is decreased by the presence of the coin 1714. Thus, when the detectorcoils 1724, 1726 have a voltage induced upon them, the phase differencebetween the voltage applied to the excitation coil 1712 and that of thedetector coils is reduced due to the eddy current effect in the coin.The amount of reduction in the phase difference is proportional to theelectrical and magnetic characteristics of the coin and thus thecomposition of the coin. By analyzing both the phase difference and themaximum amplitude, an accurate assessment of the composition of the coinis achieved.

FIGS. 65A and 65B illustrate a preferred phase-sensitive detector 1750for sampling the differential output signal V_(diff) from the twodetector coils 1722, 1724. The differential output signal V_(diff) ispassed through a buffer amplifier 252 to a switch 1754, where thebuffered V_(diff) is sampled once per cycle by momentarily closing theswitch 1754. The switch 1754 is controlled by a series of referencepulses produced from the V_(ex) signal, one pulse per cycle. Thereference pulses 1758 are synchronized with excitation voltage V_(ex),so that the amplitude of the differential output signal V_(diff) duringthe sampling interval is a function not only of the amplitude of thedetector coil voltages 1736, 1738, but also of the phase differencebetween the signals in excitation coil 1712 and the detection coils1736, 1738.

The pulses derived from V_(ex) are delayed by an “offset angle” whichcan be adjusted to minimize the sensitivity of V_(diff) to variations inthe gap between the proximal face of the sensor 1710 and the surface ofthe coin 1714 being sensed. The value of the offset angle for any givencoin can be determined empirically by moving a standard metal disc, madeof the same material as the coin 1714, from a position where it contactsthe sensor face, to a position where it is spaced about 0.001 to 0.020inch from the sensor face. The signal sample from the detector 1750 ismeasured at both positions, and the difference between the twomeasurements is noted. This process is repeated at several differentoffset angles to determine the offset angle which produces the minimumdifference between the two measurements.

Each time buffered V_(diff) is sampled, the resulting sample is passedthrough a second buffer amplifier 1756 to an analog-to-digital converter(not shown). The resulting digital value is supplied to a microprocessor(not shown) which compares that value with several different ranges ofvalues stored in a lookup table (not shown). Each stored range of valuescorresponds to a particular coin material, and thus the coin materialrepresented by any given sample value is determined by the particularstored range into which the sample value falls. The stored ranges ofvalues can be determined empirically by simply measuring a batch ofcoins of each denomination and storing the resulting range of valuesmeasured for each denomination.

If desired, the coin sorting and discrimination module 19 may bereplaced with a coin discriminating module which does not sort the coinsor a coin sorting module only. Such modules would align the coins of alldenominations in a single file and guide them past a single coindiscrimination sensor to determine whether the coins are genuine. Thecoins of all denominations would then be discharged into a singlestorage receptacle and sorted at a later time. Coins that are detectedto be non-genuine would be diverted and returned to the customer at thecoin return station 4.

When an invalid coin is detected by one of the discriminating sensorsdescribed above, the invalid coin is separated from the valid coins andreturned to the customer. In the illustrative module 8, this separationis effected outside the sorting disc by the shunting device illustratedin FIGS. 66-69. The curved exit chute 1800 includes two slots 1802, 1804separated by an internal partition 1806. The internal partition 1806 ispivotally mounted to a stationary base 1808 so that the internalpartition 1806 may be moved, perpendicular to the plane of the coins, byan actuator 1810 between an up position (FIG. 69) and a down position(FIG. 68). The exit chute 1800 is positioned adjacent an exit channel ofthe coin sorter such that coins exiting the coin sorter are guided intothe slot 1802 when the internal partition 1806 is in the down position(FIG. 67). When an invalid coin is detected by the discriminating sensorD, the actuator 1810 moves the internal partition 1806 to the upposition (FIG. 69) so that the invalid coin now enters the slot 1804 ofthe exit chute 1800. Coins entering the slot 1804 are discharged intothe tube that conveys those coins to the coin-return slot 62 at thefront of the system. While FIGS. 66-69 illustrate only a single exitchute, it will be apparent that a similar exit chute is provided at eachof the six coin exit locations around the circumference of the sortingdisc.

The actuator 1810 moves the internal partition 1806 between the up anddown positions in response to detection of invalid and valid coins.Thus, if the internal partition 1806 is in the down position and aninvalid coin is detected, the partition 1806 is moved to the up positionso that the invalid coin will be diverted into the slot 1804.Alternatively, an invalid coin may be separated from the valid coins byuse of inboard actuators in the sorting head, activated by signalsderived from one or more sensors mounted in the sorting head upstream ofthe actuators. Such an arrangement is described in U.S. Pat. No.5,299,977, which is incorporated herein by reference.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and herein described in detail. It should beunderstood, however, that it is not intended to limit the invention tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives failing withinthe spirit and scope of the invention as defined by the appended claims.

What is claimed is:
 1. A method for processing documents, comprising thesteps of: receiving documents in an input receptacle; transporting thedocuments from the input receptacle past an image scanner and adiscrimination unit at a rate greater than 800 documents per minute, theimage scanner producing images of each document and the discriminationunit producing discrimination data for each document; and receiving thedocuments in one or more output receptacles after the documents havebeen transported past the image scanner and discrimination unit.
 2. Themethod of claim 1, wherein the output receptacle is a single output bin.3. The method of claim 1, wherein the output receptacle is two outputbins.
 4. The method of claim 3, wherein one of the two output bins is anoff sort bin.
 5. The method of claim 1, wherein the documents have wideand narrow dimensions and the documents are transported with their widedimension parallel to a direction of transport.
 6. The method of claim1, wherein the documents have wide and narrow dimensions and thedocuments are transported with their narrow dimension parallel to adirection of transport.
 7. The method of claim 1, further comprising thestep of flagging documents meeting or failing to meet predetermineddiscrimination criteria.
 8. The method of claim 7, wherein the step offlagging documents comprises the step of suspending transport operationso that the flagged document is located at a predetermined position whentransport stops.
 9. The method of claim 8, further comprising the stepof receiving a user inputted discrimination value for the flaggeddocument.
 10. The method of claim 1 further including the steps of:processing the discrimination data to obtain currency denominationvalues with respect to currency documents; optically recognizing checkvalue fields within the document images of check documents; extractingcheck values from the recognized fields; and using the currencydenomination values and check values to automatically update thebalances of a financial account associated with the currency and checkdocuments.
 11. The method of claim 10, which includes the further stepsof: accepting identification from a customer associated with thefinancial account; dispensing currency to the customer; and updating thebalance of the financial account with respect to the dispensed currency.12. The method of claim 1, further including the steps of: recognizingthe certain ones of the documents cannot be identified from the documentimages/discrimination data; displaying the document image for thecertain ones of the documents on a monitor; and having a user enterinformation identifying the certain ones of the documents.
 13. Themethod of claim 12, wherein the user is a bank teller.
 14. The method ofclaim 12, wherein the information entered by the user comprises a checkvalue for a check document.
 15. The method of claim 12, wherein the useris a bank customer.
 16. The method of claim 12, wherein the informationentered by the user comprises a currency denomination value for acurrency document.
 17. The method of claim 12, further including thestep of removing the certain ones of the documents from the outputreceptacle.
 18. The method of claim 12, wherein the information enteredby the user comprises MICR data for a check document.
 19. The method ofclaim 1 wherein the discrimination data comprises authentication data.20. The method of claim 1 wherein the discrimination data comprisesdocument denomination data.
 21. The method of claim 1 wherein the imagescanner and the discrimination unit each separately optically scandocuments being transported by the step of transporting.
 22. A documentprocessing system, comprising: an input receptacle receiving documents;an image scanner; a discrimination unit; a transport mechanism operableto transport the documents from the input receptacle past the imagescanner and the discrimination unit at a rate greater than 800 documentsper minute, the image scanner producing images of each document and thediscrimination unit producing discrimination data for each document; andone or more output receptacles receiving the documents after having beentransported past the image scanner and discrimination unit.
 23. Thesystem of claim 22, wherein the one or more output receptacles is asingle output bin.
 24. The system of claim 22, wherein the one or moreoutput receptacles are two output bins.
 25. The system of claim 24,wherein one of the two output bins is an off sort bin.
 26. The system ofclaim 22, wherein the documents have wide and narrow dimensions and thetransport mechanism operates to transport the documents with their widedimension parallel to a direction of transport.
 27. The system of claim22, wherein the documents have wide and narrow dimensions and thetransport mechanism operates to transport the documents with theirnarrow dimension parallel to a direction of transport.
 28. The system ofclaim 22, further comprising means for flagging documents meeting orfailing to meet predetermined discrimination criteria.
 29. The system ofclaim 28, wherein the means for flagging documents comprises thetransport mechanism operating to suspend transport so that the flaggeddocument is located at a predetermined position.
 30. The system of claim28, further comprising an input device for receiving a user inputdiscrimination value for the flagged document.
 31. The system of claim22 further including: a processor operable to obtain currencydenomination values with respect to currency documents from thediscrimination data; the image scanner operating to optically recognizecheck value fields within the document images of check documents, andextract check values from the recognized fields; and an accountingfunctionality that uses the currency denomination values and checkvalues to automatically update the balances of a financial accountassociated with the currency and check documents.
 32. The system ofclaim 31, further including: means for accepting identification from acustomer associated with the financial account; and means for dispensingcurrency to the customer; the accounting functionality updating thebalance of the financial account with respect to the dispensed currency.33. The system of claim 22, further including: a processingfunctionality that recognizes that certain ones of the documents cannotbe identified from the document images/discrimination data; a displaydevice for displaying the document image for the certain ones of thedocuments; and a data entry device through which a user entersinformation identifying the certain ones of the displayed documents. 34.The system of claim 33, wherein the user is a bank teller.
 35. Thesystem of claim 33, wherein the information entered by the usercomprises a check value for a check document.
 36. The system of claim33, wherein the user is a bank customer.
 37. The system of claim 33,wherein the information entered by the user comprises a currencydenomination value for a currency document.
 38. The system of claim 33,wherein the information entered by the user comprises MICR data for acheck document.
 39. The system of claim 22 wherein the discriminationdata comprises authentication data.
 40. The system of claim 22 whereinthe discrimination data comprises document denomination data.
 41. Thesystem of claim 22 wherein the image scanner and the discrimination uniteach separately optically scan documents being transported by thetransport mechanism.